The Rising Tide
Time to adapt to climate changeThere is growing worldwide momentum to address the problem of climate change. We need to reduce the growth of greenhouse gas emissions and eventually bring those emissions significantly below current levels. In contemporary policy debates, efforts to achieve these goals are called mitigation.
Mitigation, however, will not suffice. Even with aggressive global efforts to reduce emissions, the Earth’s climate will continue to change significantly for many decades because of the magnitude of past emissions and the inertia of social and physical systems. Of course, many uncertainties remain about how best to reduce emissions and how the climate system will respond. But we can now say with confidence that rapid climate change and its impacts are at hand. As a result, we face immediate choices about how to temper its worst consequences for vulnerable populations and regions.
Alongside mitigation, then, we also need policies focused on adaptation, on making sensible adjustments in the face of unavoidable changes. Moreover, we need to coordinate adaptation with mitigation, as the success of each will depend on the other. Current efforts to reduce emissions will, in due course, determine the severity of climate change, and thus the degree of adaptation required—or even possible—in the future. At the same time, by discovering at what point climatic change becomes too severe for our capacity to adapt, we will learn more about what levels of emissions might engender serious danger.
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The scientific evidence for a human fingerprint on this global warming is overwhelming.
Since the second half of the nineteenth century, global temperatures have been unambiguously on the rise. The increase in global average surface temperature, as estimated by the Intergovernmental Panel on Climate Change (IPCC), is around 0.75°C (~1.4°F). Twelve of the thirteen years just prior to 2008 rank among the thirteen warmest years on record.
The scientific evidence for a human fingerprint on this global warming is now overwhelming. Emissions of greenhouse gases, such as carbon dioxide and methane, from human activities—most crucially, the burning of fossil fuels, but also agricultural practices, deforestation, and cement production—are the primary drivers, particularly of the rapid warming since the 1970s.
The greenhouse effect and its intensification by human-induced emissions of greenhouse gases are well understood and solidly grounded in basic science. Moreover, we are already seeing the impacts of warming—such troubling changes as the melting of mountain glaciers, the Greenland ice sheet, and polar sea ice; rising and increasingly acidic seas; increasing severity of droughts, heat waves, fires, and hurricanes (the intensity and frequency of extreme events can change substantially with small changes in average conditions); and changes in the lifecycles and ranges of plants and animals.
Nevertheless, the future course of climate change is deeply uncertain. This uncertainty has two central sources: what we do (globally) to reduce emissions of greenhouse gases and how the natural climate system responds to the future course of greenhouse-gas concentrations in the atmosphere. The IPCC Fourth Assessment Report (AR4) includes climate model projections based upon six “storylines,” possible future worlds with different assumptions about future population growth, levels of economic development, and potential technological advancement, as well as the rate at which such advancements are actually deployed around the globe.
In one scenario, the IPCC assumes heavy reliance on fossil fuels and significantly increasing emissions during the current century, and projects further global average surface warming of 2.4-6.4°C by the year 2100. In a second scenario, emissions grow more slowly, peak around 2050, and then fall, with expected additional warming of 1.1-2.9°C by the year 2100. The difference between the temperature ranges for the first and second scenarios reflects the influence of different trajectories for greenhouse-gas emissions on projected climate change. The ranges within each scenario also reflect uncertainties about how the climate system will respond to increasing greenhouse-gas concentrations: how much will temperatures increase in the event of a given increase in concentrations (so-called climate sensitivity)? And how will the carbon cycle and the uptake of carbon dioxide by the ocean and by terrestrial ecosystems be altered by changing temperature and atmospheric greenhouse-gas concentrations?
A temperature change of 5–7°C on a globally averaged basis is about the difference between an ice age and an interglacial period.
These different projections for warming imply very different climate change risks, affecting other climate variables (for example, precipitation patterns) as well as the likelihood of severe impacts. Warming at the high end of the range could have widespread catastrophic consequences and few benefits, save perhaps the emergence of shipping routes across the ice-free Arctic Ocean, or oil exploration in that sensitive region. A temperature change of 5–7°C on a globally averaged basis is about the difference between an ice age and an interglacial period, though this time it would occur in a century rather than, as has always been the case historically, over millennia. Alarmingly, actual emissions of the past half-dozen years exceed even the highest considered by the IPCC scenarios, which were crafted in 2000. This suggests that large increases in greenhouse-gas concentrations are in store in the next several decades unless rapid mitigating action is taken. Warming at the low end would be less damaging, but it would likely still be significant for some communities, economic sectors, and natural ecosystems. Indeed, some systems have already shown worrisome responses to the warming over the past century.
What sorts of impacts will these temperature changes lead to?
The IPCC AR4 lists many potential impacts of climate change for specific regions and highlights “key vulnerabilities,” based on seven criteria (magnitude of impacts, timing of impacts, persistence and reversibility of impacts, potential for adaptation, distributional aspects of impacts and vulnerabilities, likelihood of impacts and vulnerabilities and confidence in those estimates, and the importance of the vulnerable system[s]). Possible impacts include the loss of glaciers and the advent of other factors producing rising sea levels, which could inundate low-lying coastal areas and small island nations around the world; escalating infectious disease transmission and other risks to human health; increases in the severity of extreme events such as heat waves, storms, floods, and droughts; large drops in farming productivity, especially in hotter areas; the loss of cultural diversity; and an escalating rate of species extinction. Many of these problems are already emerging in some areas.
As glaciers melt, for example, sea levels rise and water becomes scarcer in regions that depend heavily on glacier-derived water for their dry-season water supply. In South America, shrinking glaciers could put a large fraction of the population west of the Andes at risk. According to one study, glacier-covered areas in Peru have experienced a 25 percent reduction in the past three decades. The authors note that “at current rates some of the glaciers may disappear in a few decades, if not sooner,” and warn of the irreplacable loss of fossil water.
Devastating events such as the 2003 European heat wave illustrate that large vulnerabilities exist even in developed countries.
China, India, and other parts of Asia are even more vulnerable. The ice mass in the region’s mountainous area is the third largest on Earth following Arctic-Greenland and Antarctica, and as its glaciers vanish in the coming decades, diminishing water supplies will affect vast populations. The Chinese Academy of Sciences has announced that the glaciers of the Tibetan plateau are vanishing so fast they will shrink by half every decade. Researchers estimate that enough water permanently melts from them each year to fill the entire Yellow River.
Furthermore, climate change is already having significant impact on human health, particularly that of vulnerable populations and those with little capacity to adapt. For example, the increased frequency and intensity of heat waves put small children and the elderly at risk. These populations are at greatest peril where air conditioning is unavailable or unaffordable, but devastating events such as the 2003 European heat wave, now linked to the premature deaths of at least 35,000 people, illustrate that large vulnerabilities exist even in developed countries.
Increases in the frequency and intensity of floods, hurricanes, fires, and other extreme events are also troubling. They injure human health both directly and indirectly, as when smoke from wildfires damages air quality, exacerbating respiratory illnesses in downwind areas.
In some regions—particularly the Arctic, where surface air temperatures have warmed at approximately twice the global rate—climate patterns are threatening entire ways of life. Traditional hunting groups and coastal indigenous communities have had to alter their social, cultural, economic, and political lives. The island village of Shishmaref, off the coast of northern Alaska, has been inhabited for centuries. Its 600 current residents are facing the real possibility of evacuation. Rising temperatures are melting sea ice (which allows higher storm surges to reach the shore) and thawing permafrost along the coast, increasing shoreline erosion and undermining homes and water systems. The absence of sea ice in the fall makes traveling to the mainland to hunt moose and caribou more difficult. Inuit hunters in Canada’s Nunavut Territory report thinning sea ice, declining numbers of ringed seals, and new insect and bird species in their region. In the western Canadian Arctic, Inuvialuit are observing more thunderstorms and lightning—formerly very rare in this region. Norwegian S√°mi reindeer herders report that prevailing winds they rely on for navigation have become more variable, forcing them to change their traditional travel routes. Unpredictable weather, snow, and ice conditions make travel hazardous, endangering lives. The precise links of these local changes in weather patterns to climate change are difficult to establish, but they are illustrative of the broader risks of extreme events.
Depending on the severity of its impacts and the rates of response among individual species, climate changes could dismantle existing plant and animal communities.
With regard to biodiversity, important biological events for many plants and animals now occur earlier in the spring as a result of climate changes. And many species are moving poleward, up mountain slopes, or both. Scientists have found that coastlines and mountaintops are especially prone to irreversible losses. If these “geoboundaries” become inhospitable to their present occupants, extinction will be much more likely for many of the species that dwell there. Depending on the severity of its impacts and the rates of response among individual species, climate changes could dismantle existing plant and animal communities. This is worrisome not only for the loss of biodiversity, but because of the potential disruption of ecosystem “goods”—seafood, fodder, fuel wood, timber, pharmaceutical products—and “services”—air and water purification, flood control, pollination, waste detoxification and decomposition, climate moderation, and soil-fertility regeneration.
Finally, the IPCC suggested that climate change could trigger “surprises.” These are fast, nonlinear climate responses, thought to occur when environmental thresholds are crossed. Some of these surprises could actually be anticipated, but others may be truly unexpected. “Imaginable surprises,” include the collapse of the large-scale North Atlantic ocean circulation—which could cause significant and potentially rapid cooling in parts of the North Atlantic region—and the deglaciation of Greenland or the West Antarctic ice sheets, which would, over many centuries, cause a considerable rise in sea level, threatening many coastal cities and low-lying coastal areas such as river deltas. There is also the possibility of true surprises, unimaginable because of the enormous complexities of the climate system and the interrelationships between oceanic, atmospheric, terrestrial, and other systems.
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Faced with these grave risks, and great uncertainty, what should we do? While we cannot know the precise temperature increase and consequences likely to result from future emissions, we do know a few things with confidence. We know that cutting back emissions will reduce the level of temperature increase that would otherwise occur and thus reduce climate change risks: that is why mitigation is so important. But we also know that some further climate change will occur no matter how quickly we are able to reduce emissions. We know, too, that emissions are increasing rapidly, and are, as decribed above, at higher levels than assumed in the most dire IPCC scenario. The combination of historical and currently increasing emissions levels has locked in further warming for many decades. Therefore, we need both mitigation and adaptation.
How can we get the right mix?
Mitigation and adaptation have often been presented as tradeoffs, as if efforts to adapt to climate change will attenuate efforts to reduce greenhouse-gas levels, and vice versa. The assumption seems to be that each would divert attention and resources from the other. But there is growing recognition that the two policies must be complementary and concurrent.
There are limits to adaptation, particularly if warmer temperatures spur increased use of air conditioning, and therefore less acclimatization.
Mitigation can keep warming on a lower trajectory, and delays in mitigation will lock in further warming, making adaptation that much harder. Adaptation, in contrast, is a response to warming, not a means of slowing it. It is necessary as a response to the impacts associated even with lower-emissions scenarios. Because of the decades of inertia in both climatic and economic systems, the benefits of mitigation take time to materialize, so adaptation is essential in responding to near-term climate changes. Failures to adapt could be disastrous.
Mitigation and adaptation also yield fundamentally different benefits and have correspondingly different policy implications. Mitigation provides long-term, global gain. A central challenge of mitigation policy, then, is to balance global factors: responsibility for historical emissions, growth in current emissions, and capacity to reduce emissions vary widely among nations. The benefits of adaptation strategies, in contrast, are both more immediate and more focused on specific regions and sectors. Given the wide range of climate change impacts on different regions, groups, and sectors, the need for adaptation varies widely as well.
The IPCC described two types of adaptation: autonomous and planned. Autonomous adaptation is not guided by policy; it is a reactive response prompted by the initial impacts of climate change. Consider a physiological example of autonomous adaptation. People who now live in warmer areas have acclimatized to those conditions, becoming less vulnerable to temperatures that would cause significant heat-related illnesses for people living in more temperate areas. Even so, there are limits to such adaptation, particularly if warmer temperatures spur increased use of air conditioning, and therefore less acclimatization.
Planned adaptation can also be reactive. For example, after the 2003 European heat wave, European countries instituted more coordinated plans to deal with periods of extreme heat. Buying additional water rights to offset the impacts of a drying climate or purchasing crop insurance where available are also reactive responses.
Adaptations to slowly evolving trends embedded in a noisy background with a great deal of variability are likely to be delayed by decades.
Reactive adaptations to climate change will almost certainly not be fast or easy. Some have argued that farmers adapt to changes in markets, technology, and climatic conditions when necessary. But a large number of factors are bound to complicate such adaptations: farmers may resist unfamiliar practices, have difficulties with new technologies, or face unexpected pest outbreaks. Moreover, the high degree of natural variability of weather may mask clear identification of emerging climatic trends. Adaptations to slowly evolving trends embedded in a noisy background with a great deal of variability are likely to be delayed by decades as farmers attempt to sort out true climate change from random fluctuations. Imagine a sequence of weather anomalies: say, a series of very dry years, which are precisely the opposite of what a long-term climatic trend toward wetter conditions would lead one to anticipate. Such a sequence could easily be mistaken for a new climatic regime and actually lead to maladaptive practices, such as investing in additional water storage that becomes unnecessary, instead of investing in better flood protection.
Another kind of planned adaptation—anticipatory or proactive—has greater policy potential. Anticipatory adaptation might include improving or expanding irrigation for agriculture, engineering crop varieties that are better able to cope with changing climate conditions, building sea walls to protect coastal infrastructure, and constructing reservoirs or implementing water recycling strategies to improve water management. Such actions may be similar in substance to reactive adaptation, but they anticipate future changes rather than responding to past shifts.
One region, among many, that could benefit greatly from adaptive initiatives is California. With its Mediterranean climate of wet winters and dry summers, California relies heavily on melting snow pack stored in the Sierras for agricultural and urban water supply. Warming is expected to reduce the snow pack considerably as more precipitation falls as rain instead of snow and the snow pack melts earlier in the year. Proactive adaptations are now under consideration, and they might include regulatory and political actions: connecting protected lands to create wildlife migration corridors, setting up networks to disseminate climate information and potential adaptive actions, and creating insurance mechanisms or support funds for disadvantaged and vulnerable groups that might not have the capacity to adapt on their own. Some of these actions would also foster sustainable development.
However, even if policies to facilitate adaptation are instituted, maladaptation can still occur. Such actions can be more damaging to developing countries and marginalized groups who have limited financial and other resources than not adapting at all. For them, even one round of successful adaptations will be taxing, let alone multiple rounds when the early measures prove misguided. A generally effective near-term strategy will need, then, both to identify and address immediate threats, and to strengthen the ability to cope with climate variability, while also anticipating that we may face more intense and/or more frequent extreme events than we have seen historically. Such an approach would build resilience and a capacity to make new adaptations while new information regarding the trajectory of future climate change becomes available.
Most developed countries have long underinvested in sustainable development, with or without the prospect of climate change.
But the near term cannot be our only focus. There are certain areas that require long-term planning to avoid severe impacts, planning that may take the form of investments in long-lived infrastructure in coastal zones or habitat protection for threatened or endangered species. In these cases, paying attention to the full range of climate projections over the next century is important. Furthermore, good policy coordination—explicit consideration of the interactions of adaptation policies across sectors and regions, as well as the interactions between adaptation and mitigation—is crucial. For example, certain adaptations, such as recharging groundwater to increase water supply, may be energy-intensive. If the energy is generated from fossil fuels, the result may be to increase greenhouse-gas emissions.
Anticipatory adaptation is an investment. Most studies about its potential assume that countries and groups can afford such investment. Unfortunately, this is not universally true, especially for countries where development is a priority. Several funds have therefore been established to foster adaptation in developing countries, the best-known being the so-called Marrakech Funds (established at the seventh Conference of the Parties in Marrakech, Morocco in 2001) and the Global Environmental Facility’s (GEF) Climate Change Operational Programme, funded by world governments. These funds are a promising development, but guidelines for determining which adaptation projects deserve funding are lacking. The GEF requires such projects to show “global environmental benefits” and the Marrakech Funds try to assure funding of adaptation to long-term climate change rather than to short-term climate variability. Yet adaptation projects are hard to assess on these grounds because they are local (and therefore bring local, rather than global, benefits) and will likely improve an area’s ability to adapt to climate change and climate variability even if they focus immediately on the short-term. Moreover, the funds available are probably much less than the needed amount. Most developed countries have long underinvested in sustainable development, with or without the prospect of climate change. Likewise, adaptations to help the most vulnerable—often those who contributed the least to the accumulation of greenhouse gases in the atmosphere—are significantly under-funded.
Indeed, planned and autonomous adaptation both have their limits. Sensitivity to changing climate conditions may be higher than currently estimated. Without significant mitigation of greenhouse-gas emissions, warming and the intensity of climate impacts may exceed the coping capacity of these measures.
Relocating species to new areas may have unintended consequences for the ecosystem into which the species are introduced.
A third form of adaptation, more drastic than autonomous and planned, is called geoengineering. Schemes to modify environment systems themselves or to control climate have been proposed for more than fifty years as efforts to, say, increase temperatures in high latitudes, increase precipitation, decrease sea ice, create irrigation opportunities, or offset potential climate change. Various proposals would inject iron into the oceans or sea-salt aerosol in the marine boundary layer or spread dust in the stratosphere to reflect an amount of solar energy equivalent to the amount of heat trapped by increased greenhouse gases.
In a similar vein, a variety of ecoengineering strategies have been proposed to use managed relocation or colonization as a way to prevent extinction of species that are unable to adapt independently to climate change. But relocating species to new areas may have unintended consequences for the ecosystem into which the species are introduced. It will be a difficult ethical dilemma to assess whether moving a species threatened with extinction at the top of a warming mountain to another taller mountain, thereby turning it into an invasive species at its new home, is justified.
These approaches—geoengineering and ecoengineering—attempt to offset the effects of one manipulation of the Earth system (climate change) with another large-scale manipulation of physical or biological systems. Recent geoengineering schemes have been championed as a cheaper method of counteracting climate change than conventional emissions-reduction strategies, an intervention that responds to foot-dragging by governments, or a unilateral alternative to global coordination.
But while proponents—including industries negatively affected by climate-control policies—argue for geoengineering on grounds of cost-effectiveness or as a last resort, critics express skepticism that any geoengineering scheme would reliably work as planned or that the long-term international political stability and cooperation needed to maintain such schemes is possible. Moreover, geoengineering risks transnational conflicts; such activities may produce—or be perceived to produce—damaging climatic events, and thus provoke political conflict. These controversial schemes are desperate measures: understandable, but not what the current situation demands. In reducing risks, nothing can substitute for the hard work of aggressive mitigation combined with anticipatory adaptation.
In a framework of distributive justice, priority should go to disadvantaged countries and groups.
Even with an optimal mix of mitigation and adaptation, however, the results may still be unfair. The most marginalized groups often have limited access to information, little political or economic power, and therefore limited influence over decisions: much less than people with political and economic power, who are generally less vulnerable to climate change damages. Hence, policies cater to such special interest groups as the coal industry or to the United States, China, and other powerful countries at the expense of more needy groups or nations.
To avoid overlooking already-marginalized groups when forming local, national, and international climate policy, decision-makers need to consider the effects of actions and inactions on the distribution of people’s well-being and the sustainability of other species. In a framework of distributive justice, priority should go to disadvantaged countries and groups. Side payments from the prime sources of the problem (generally, richer countries) to those who have contributed less of the problem (generally, less-developed countries) and have less ability to fix it can also be fashioned for fairness and political cooperation (for example, agriculture or clean-energy technology transfer, or assistance for population mobility). Both the direct effects of climate change and the differential impacts of climate policy can lead to inequitable results for the many populations grappling with this worldwide phenomenon.
Thus, good governance in the realm of climate policy will require protecting the planetary commons by mitigating emissions, initiating smart adaptations and improving adaptive capacities, and dealing on fair terms with those most disadvantaged by either climate impacts or impacts of climate policies.
Vulnerability assessment is essential to the progress of adaptation. It is an important tool for informing the development of climate change policies, particularly adaptation strategies. Vulnerability depends on exposure to a stress, susceptibility to that stress, and capacity to adapt or respond to it. With climate change as the source of stress, mitigation reduces vulnerability by reducing exposure, while adaptation reduces vulnerability by turning adaptive potential into adaptive capacity.
The distinction between adaptive potential and adaptive capacity is critical. We know that the vulnerability of New Orleans to a direct hit by a Category III hurricane was much higher than was widely believed prior to Katrina, though a few academics and engineers had been issuing warnings for decades. Adaptive potential was quite high—for example, levees could have been strengthened in advance—but this potential was not realized, and therefore adaptive capacity was low. In general, adaptive capacity is related to the level of development in a country. But events such as Katrina (affecting primarily poor residents), and the 2003 heat wave in Europe (affecting primarily the elderly) highlight the vulnerability of specific populations and regions, even within highly developed nations.
Even as the world struggles to fashion fair and effective forms of mitigation, adaptation will be essential to minimize the worst consequences of climate change.
Assessing vulnerability to climate change is a complex matter. It requires analysis of climatic conditions and potential impacts, projections of future impacts in the context of alternative socioeconomic development paths, and an evaluation of how well different adaptation strategies will do at reducing vulnerabilities. Detailed understanding of the affected sectors, communities, and management systems; the interactions of non-climatic stressors with a changing climate; and each system’s ability to respond to changing conditions are often lacking. There is a critical need for research that couples climate projections with studies of vulnerability that focus on specific economic sectors (agriculture, services, manufacturing), specific regions, and specific groups. And these need to be generated in close communication with relevant stakeholders to increase the potential usefulness and likelihood of actual use of such knowledge in choosing adaptations.
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Given the uncertainties in climate science and impact estimates, we need to reduce considerably the rate at which we add to atmospheric greenhouse gas levels. This will give us more time to understand climate risks and to develop lower-cost mitigation options while making climate surprises less likely. Greenhouse-gas abatement policies will provide incentives to invent cleaner, cheaper technologies, and developed countries should aggressively lead that effort, both because of their historical contribution to the problem and their greater capacity to help.
Simultaneously, the needs of developing countries and marginalized groups should be accommodated through coordinated adaptation and mitigation actions. Developed countries should shoulder this burden as well, as required by the United Nations Framework Convention on Climate Change. When leaders of developing countries say they will not join mitigation efforts until they catch up with OECD countries in per capita emissions, and some OECD countries assert that they won’t abandon fossil-based energy generation that props up their economic growth, we face real, potentially catastrophic environmental danger. We will need international negotiations and bargaining to help the developing world leapfrog the traditional technologies of growing economies—such as massive coal burning or dramatic increases in individual car use. Lower-emitting technologies such as electric vehicles and alternative energy sources can be implemented at much faster rates with cooperation and political will.
Slowing down pressure on the climate system and addressing marginalized- country and group needs are the main insurance policies we have against potentially dangerous, irreversible climate events and the injustices that will inevitably accompany them. Even as the world struggles to fashion fair and effective forms of mitigation, adaptation will be essential to minimize the worst consequences of climate change.
Comments
About the Author
Michael D. Mastrandrea is research associate at the Woods Institute for the Environment at Stanford University. He contributed to the International Panel on Climate Change (IPCC) Fourth Assessment Report in 2007.
Stephen H. Schneider, Melvin and Joan Lane Professor for Interdisciplinary Environmental Studies and Stanford University, was Coordinating Lead Author of the IPCC's working group on Impacts, Adaptation and Vulnerability, from 1997-2001.
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BR Footnote:
Boston Review’s intern blog
"The scientific evidence for a human fingerprint on this global warming is now overwhelming."
What, again, is that evidence? I wish to be overwhelmed.
You say that temperatures have been rising, but that is not to say that man has caused it. You say that our emissions of greenhouse gases have been increasing, but that is not to say they have raised the temperature.
None of the "troubling changes"—the impacts of warming—that you mention have been beyond the historical range of natural variation and some are not in fact occurring, such as "rising seas".
Your long, thoughtful consideration of the next several decades rests on the observed evidence, yet you do not tell us what it is.
Your detailed, intelligent analysis of how to cope with a difficult future depends upon proof of global warming being caused by man's activities, yet you withold it from us.
Do you consider that thinking people will forgive this serious omission, or that they will somehow fail to notice it?
Whichever is true, it is strange indeed that men of your obvious intelligence can be so stupid. For why should we listen to your prescriptions when you offer no evidence that your hypothesis is true?
Who do you think you're speaking to?
Cheers,
Richard Treadgold.
Your article seems to take it for granted that the Earth is warming, and will continue to warm in accordance with IPCC predictions. Yet neither of these facts are true.
Having warmed for a period up to 1998/9, the Earth's temperature then stayed static, and for the last few years has been falling rapidly, in spite of continuing CO2 output. This has meant that ALL the IPCC predictions have proven completely untrue, and effectively disproves the assumed link between temperature and CO2.
Yet you behave as if the last 8 years have not happened. Why is this?
http://www.dailyexpress.co.uk/posts/view/69623
Excerpt:
At the beginning of this year there was a BBC show with four experts saying: “This is going to be the end of all the ice in the Arctic,” and hypothesising that it was going to be the hottest summer ever. Was it hell! It was very cold and very wet and now we’ve seen evidence that the glaciers in Alaska have started growing rapidly – and they’ve not grown for a long time.
I’ve seen evidence, which I believe, that says there has not been a rise in global temperature since 1998, despite the increase in carbon dioxide being pumped into the atmosphere. This makes me think the global warmers are telling lies – carbon dioxide is not the driver.
The idiot fringe have accused me of being like a Holocaust denier, which is ludicrous. Climate change is all about cycles, it’s a natural thing and has always happened. When the Romans lived in Britain they were growing very good red grapes and making wine on the borders of Scotland. It was evidently a lot warmer.
If you think the portions of the scientific and policy communities that accept the reality of anthropogenic climate change are steamrolling you, you are not doing your due diligence in educating yourself on the subject. At one point I would have agreed that the "denier" appellation was unscientific and, indeed, offensive, but, at this point, it's apt.
In any case, Mastrandrea and Schneider don't really know what's going to happen, and I think they may occasionally reach farther than prudent caution and into the realm of overreaction, but the scientific debate over climate change does appear to be over. These guys aren't taking warming for granted--they've followed decades of increasingly persuasive research and are now moving on to the next stage: crafting a sound policy.
There is still a mountain of literature available to read on the internet from noted scientists in a number of fields including climate science, and if anything it's the skeptics that are growing in number.
The only place the debate is over is in the mainstream media and politics. The scientific community as a whole certainly don't think it's over.
To pick up on one of the points from the article link in #4. To dimiss the decline in temperatures as natural variation masking CO2 warming is completely absurd. If the cooling is a result of natural variables that the models didn't predict or allow for, how can we be expected to trust our future to these obviously flawed models. That alone is enough to tell me that saying "The debate over evidence is laid to rest" is completely wrong.
Do you guys remember waiving your hands in front of your little sister's face on long car rides?
"I'm not touching you... I'm not touching you..."
Damion Greer - "I agree that the authors don't do a great deal to explain the evidence, but there are plenty of places where you can find that."
You smudge the point, which is not that they have failed to explain the evidence, but to reveal any.
Telling us to find it elsewhere simply avoids responsibility.
"…you can bet the data is, at last, overwhelming." I don't want to bet on the data, I want to see the data. You can't persuade people like that. You must show them the evidence; somebody showed it to you, didn't they? So come on, what is it?
Whistle - I wish I could tell what you're talking about. I hope you're all right. Oh, and check the spelling of wave.
Cheers.
That's what I mean when I say I agree with you—they should state which evidence they find persuasive, though I don't think it is their responsibility to explain it in exhaustive detail. After all, this isn't a scientific journal. But you don't have to look there for the evidence either. The data is everywhere. You can, for example, read the IPCC report online. If you truly want to see the data, as you claim you do, you will read that.
Alternatively, the article I linked in my post above points to some other important data in a more accessible format. Boston Review had an article a couple of years ago (which is now a book) by an MIT professor explaining that among the factors scientists have found convincing are the results of computer models. Obviously, real experimentation would be best, but the climate is an arena that doesn't allow for easy experimentation, so computer simulations are the next best thing.
We know that the simulations are useful because they mirror past observations with great accuracy. In other words, we have the equations and parameters necessary to produce a model that comports with observed reality. If we use the same parameters that produced results in accordance with past observations, we find that observations from the late 1960s onward (it depends on the simulation, but they group around that time period), in particular, do not comport with the computer model. There is a strong and consistent divergence: the model predicts consistently lower temperatures than have been observed. But when increased concentrations of human-generated greenhouse gasses are incorporated into the equations, one finds that the new simulation results match observed temperatures very well.
Now, you could argue that the simulations are designed to produce the results the scientists are looking for. The scientists know that there are other factors that could account for the warming trend but they have purposely omitted them from their equations and parameters. This, however, would entail a wide-ranging conspiracy that, one would have to admit, is profoundly unlikely.
More plausible is that there are systematic errors involved in the simulation building process, and surely there are, but would they yield these sorts of results? What kind of error would allow the simulation to accurately mirror past observations (i.e. from the earliest days of comprehensive climate measurements until the late 1960s) but consistently underestimate more recent ones?
The only potentially valid error I can conceive of is that there is some explanation other than greenhouse gasses that, when factored mathematically into the simulation, realigns the curves. However, a rigorous scientist would try out these other variables, and I suspect that many have, although I can't say for sure because I haven't read the journals. I would not be able to understand them if I tried. (Actually, I would appreciate it if a qualified individual would point out what kind of work in this area has been done.) These explanations might include phenomena related to changing earth ecology, certain "celestial" factors that I have no understanding of, subtle changes in the Earth's magnetic field, and I don't know what else. But I am certain that if these factors can be measured and their effects understood and incorporated into the computer models, they have been.
The physical evidence (core samples, decreasing ice mass, etc.) is available ad nauseum in the IPCC report.
All of this involves a great deal of uncertainty, but not so much uncertainty as to be beyond usefulness. That simulations are able to accurately model the climate of bygone days without incorporating human-generated greenhouse gasses tells us that the models are well-calibrated. That there is no way to make the model fit the past forty plus years without introducing the human variable tells us that humanity is having an impact on the climate, just as other forms of life (e.g. everything green on planet Earth) do and always have.
Reliance on computer models does run the real risk of bad science. In response to observations that do not comport with predicted behavior, scientists need to be willing to alter their models to account for new data. And if, after constant tinkering, the model continues to fail, it may need to be scrapped altogether. But existing models have done well at mirroring past climates so, for now, they seem useful. And to the degree that they ARE useful the most rigorous research we have available shows anthropogenic warming.
Damion, you refer to evidence in your first paragraph then spend the rest of your lengthy (and admittedly interesting) post talking about models. But models are not evidence of any kind.
If models match history it's because they are told to do so, not because the modellers understand the climate. They don't understand it.
The IPCC don't believe the models match the future, since they don't pick a 'scenario', they give us a dozen or so and let us choose for ourselves.
The models do not predict that CO2 leads to increased temperatures, they are told that it does. If they match historical temperatures "only" when anthropogenic emissions are included, it is not evidence of an anthropogenic influence. It is evidence the scientists don't know what else it could be. (So it must be man-made.)
The models failed to forecast the last decade or so of flat and falling temperatures, and all El Ninos and La Ninas. If they cannot forecast the first few years of the climate with any skill, what hope can we have they will succeed over 100 years?
There is a readable summary of all this at http://www.climate-skeptic.com/2007/09/chapter-5-skept.html.
I appreciate your level-headedness over a difficult topic, Damion, but my question remains simple. Of course, it was originally directed to the authors of this article.
As to evidence obliquely referred to by you: core samples are not evidence of present warming; decreasing ice mass is determined by reduced precipitation, not air temperature; and, anyway, no evidence of warming speaks to man's involvement in that warming.
To sum up: the atmosphere is not warming, but cooling; the models are not validated; nobody understands the climate perfectly; there is evidence that solar output drives our temperature. We don't want to ruin the economy without better cause!
Only evidence will persuade intelligent hearts and minds of the truth. Indeed, just the mere existence of evidence is required—all else is but a vain flapping of the lips.
That is why I continue to repeat my question: What is the evidence?
Cheers.
I remember pretending that my little sister WASN'T EVEN THERE when she was right in the room with me. It drove her crazy!
Please note the periods of warming and cooling in this graph of lower tropospheric temperature anomalies since 1978. Note especially that in the last seven years, though the temp goes up and down, there is no clear trend until a pronounced descent over the last eighteen months.
Note that there is no evidence of warming while the temperature remains level or descends.
So again, what is the evidence of global warming?
Cheers.
Cheers.
Thank you. The first point to note is that I didn't mention 1998. I was discussing the evidence for man-made global warming. Actually, if one could "ignore" 1998, the UAH record goes right back, with wiggles, to about 1980 with very little trend.
Still, there are some other things to say about El Nino et al.
None of the climate models predicted the giant El Nino of 1998, or any other, or any La Nina. So the models don't do weather all that well, do they? Not as well as many people presume they do. And all that means is that the modellers don't understand climate as well as we wish they did.
It's an interesting article, and everyone should take the point that meteorological issues become more complex the closer one looks. There is much more, for example, to warming the oceans than one might think.
The article says: "Global warming has certainly not stopped, even if average surface temperatures really have fallen slightly as the Hadley figures suggest."
First, the Hadley figures don't suggest, of course, since they are numbers. The author seems to like the Hadley dataset, as he quotes it extensively; let us assume, then, that he believes it. So this statement means that he agrees that average surface temperatures have fallen slightly. That's a bit strange, since he's just gone to some trouble to persuade us that they have not fallen. Definitely ambiguous.
But more importantly, it is an undeniable fact that, in the absence of a rising average temperature, global warming has indeed stopped. You are free to predict a resumption, and if you propose a reasonable hypothesis for that then people will agree with you. But reason could never agree that warming could occur during decreasing temperatures because it's ludicrous—like saying you risk sunburn because snow is falling.
You cannot have them both at the same time; warming and cooling are mutually exclusive. End of story.
The simple fact is, that in the absence of warming for a period of years, people are going to enquire into the facts of the global warming theory. They will want to know why the air is not warming, when it has been firmly predicted.
In any case, temperatures may rise and fall as they always have, but what the article asserted is that humans are responsible for it. They simply failed to show us the evidence.
I'd like to know about that.
Cheers.
The evidence suggests you wouldn't last three rounds in a cage match with Willard Scott.
You kick enough sand about average global temperature, you just might be the Hero of the Beach!
Still, I wouldn't want to just pick on your rhetorical style: you're actually talking out of both sides of your mouth. In your June 9 article "Why pick on carbon dioxide?" you state it plainly--
"Picking on CO2 is a strange development for two reasons: first, because it is axiomatic that life forms do better where it is warmer.
...
The point is that we have been induced to fear what we actually prefer. What, really, is wrong with a little warming? By a little, I mean perhaps 3°C—a moderate prediction for the end of this century. Three degrees will hardly boil water, will it?"
So which is it, Rick? Are we getting warmer or colder? Or are you hoping to get some use out of that Antarctic time-share?
http://www.climateconversation.wordshine.com/docs/rt001_why_pick_on_carbon_dioxide.htm
The sarcastic use of the word "evidence" means some will never be satisfied with an answer. You know, there is no PROOF that tobacco and cigarettes cause cancer - there are only high confident correlations between smoking and cancer. And the confidence is high enough to win court cases and compel warning labels. I don't smoke. And I urge others to believe the science.
Of course a noble experiment would be for humans to radically reduce CO2 output and then observe changes to atmospheric CO2 levels and attendant cooling. I prefer that experiment to continued pollution.
You might want to follow the recent EPA decisions about regulating CO2.
My CO2 article in June attempted to refute the hypothesis that CO2 will be responsible for dangerous warming. It did not say that warming will occur and it does not conflict with my comments above that warming is not occurring right now.
Draw the lines, connect the dots, do whatever you must, but please show us the evidence that man is responsible for warming the planet to a dangerous degree.
Cheers.
We're not talking about smoking.
I know some seem to demand 100%, water-tight, cast-iron, guaranteed 'proof' of dangerous AGW before they're prepared to consider a case for doing something about it. That's not my position.
I would like to know what has convinced you and others to call the emission of CO2 (hitherto the well-known minor atmospheric gas required by plants for growth through photosynthesis) "continued pollution".
That's all. I presume some evidence lies behind your decision, so tell us what it is, please. Not evidence of increased CO2, but of its causal role in dangerous warming.
And of course, I mean evidence, not more polemics, if you don't mind.
Cheers.
A decision by a public servant is not scientific evidence of dangerous man-made global warming.
It may, or may not be, evidence of his adherence to instructions.
CO2 feeds us all, through its nourishment of plants. It is not a pollutant of any kind.
The 'noble experiment' you propose can of course easily be conducted by examining history. As CO2 levels rose, the hypothesis says temperature should have risen, too; so did they?
Say the increase in CO2 is taken as starting in 1750. What correlation do you find between CO2 and temperature until 1800? Or until 1900? Or since 1900? Do you find any correlation at all?
Or is the picture more complex than that, and you acknowledge that other drivers are present? Do let us know. It's fairly important to your theory.
Cheers.
William
http://mtkass.blogspot.com/2009/02/malthus-pyramid-schemes-starvation.html