As you’ve probably noticed in the news, the second of four assessment reports on climate change has been announced; the summary for policymakers details the main findings of the report. The first report summarised the scientific evidence of climate change and the probable future changes in climate.
The first report said “this is what is happening and what will probably happen”; this report says “these are the effects and dangers to the ecology and to us”, including water resources, species impacts, land-use and coastal effects, agricultural changes, etc. It is the first of the reports that tells us why we should be worrying about it and what we will probably have to cope with.
Because it is talking about impacts and addresses things that need to be done, some of the news media indicates increased political pressure to moderate the language in the report. Some of the scientists have decided to remove themselves from the IPCC in protest over some of the pressure applied. So when you read the summary for policymakers look for language that tries to water down the impact of results, and take it in context with the main message. Also, it might be better to err towards more significant impacts if you want to get a better idea of the consensus.
It is interesting that much of the research on biological impacts has been done in Europe; 28,000 of 29,000 observational data sets, most of them from the 6 year period since the last assessment report, come from EU countries. The European Union has consistently been the most responsible political unit regarding ecological issues over recent history. However, the greatest pressure to tone down the level of certainty in the document came from the United States, China, and Saudi Arabia, according to CBC News.
Finally, the new report talks about regional (i.e. continental) impacts. From a quick read-through, the areas that will suffer the worst seem to be the polar regions, Africa mainly due to droughts, coastal Asia (especially the mega-delta regions such as Bangladesh). For North America and the Arctic (our bailiwick) some of the findings are as follows (as quoted from the report):
- Already Arctic human communities are adapting to climate change, but both external and internal stressors challenge their adaptive capacities. Despite the resilience shown historically by Arctic indigenous communities, some traditional ways of life are being threatened and substantial investments are needed to adapt or re-locate physical structures and communities.
- In the Polar Regions, the main projected biophysical effects are reductions in thickness and extent of glaciers and ice sheets, and changes in natural ecosystems with detrimental effects on many organisms including migratory birds, mammals and higher predators. In the Arctic, additional impacts include reductions in the extent of sea ice and permafrost, increased coastal erosion, and an increase in the depth of permafrost seasonal thawing.
- Beneficial impacts would include reduced heating costs and more navigable northern sea routes.
- In both polar regions, specific ecosystems and habitats are projected to be vulnerable, as climatic barriers to species’ invasions are lowered.
- Moderate climate change in the early decades of the century is projected to increase aggregate yields of rainfed agriculture by 5-20%, but with important variability among regions. Major challenges are projected for crops that are near the warm end of their suitable range or depend on highly utilised water resources.
- Disturbances from pests, diseases, and fire are projected to have increasing impacts on forests, with an extended period of high fire risk and large increases in area burned.
- Cities that currently experience heat waves are expected to be further challenged by an increased number, intensity and duration of heat waves during the course of the century, with potential for adverse health impacts. The growing number of the elderly population is most at risk.
- Coastal communities and habitats will be increasingly stressed by climate change impacts interacting with development and pollution. Population growth and the rising value of infrastructure in coastal areas increase vulnerability to climate variability and future climate change, with losses projected to increase if the intensity of tropical storms increases. Current adaptation is uneven and readiness for increased exposure is low.
You’ll note that many of the findings are similar to previous predictions. The most important thing you should take away from this, and the difference with previous results and predictions, is that there is a lot more hard evidence supporting these statements. The 29,000 data sets I mentioned earlier show trends consistent with temperature changes as predicted by global warming, or directly show temperature change over the last few decades in the areas studied. Also, the Working Group I report that came out earlier this year show strong measured physical evidence of global and regional climate warming. The previous reports depended more on model extrapolations, but there was little data to validate against the models; now there is.
The next two reports are going to be the most interesting, since they will talk about “solutions” and will encourage governments to make responsible decisions. I expect a lot of spin. The next report will be by the Working Group III (Mitigation). This will be approved on May 4, 2007, in Bangkok. It will summarise the international consensus on how we are to cope with the effects of climate change for both the near-term and long-range impacts. In November the synthesis report will be announced in Valencia, Spain.
The problem isn’t simple, the impacts are complicated and interconnected, and mitigation will have to address all of this together with international political interests. But the more we know the more we will be able to respond with effective actions. And governments will understand what needs to be done, and why they are doing it.