The latest US Federal Advisory Committee Draft Climate Assessment Report should silence climate change deniers, but, of course, it won't. The third National Climate Assessment is the work of more than 240 climate scientists and, after extensive review from the National Academies of Sciences, is awaiting submission to the federal government pending further review. The report draws mostly from studies done in the US, but since climate patterns don't respect national borders it can be assumed that its conclusions can be universally applied; as well, much of the data was compiled globally.
In its introduction the report says, "Continued warming and an increased understanding of the US temperature record, as well as multiple other sources of evidence, have strengthened our confidence in the conclusions that the warming trend is clear and primarily the result of human activities."
The report also says heavy precipitation and instances of extreme heat are increasing in a manner consistent with model projections and the risks of such extreme events will rise in the future, and calls the continuing sharp decline in summer Arctic sea ice "unprecedented" and "consistent with human-induced climate change". Other crucial findings are that the global sea level has risen by about 23cm since reliable record keeping began in 1880, and if carbon dioxide emissions stay on the same upward trajectory it is projected to rise another 0.3-1.2m. What's more, if we stay anywhere near our current emissions path, average land temperatures across the continental US are projected to rise a minimum of 5C in the later part of this century.
The report says: "A certain amount of continued warming of the planet is projected to occur as a result of human-induced emissions to date ... even if all emissions from human activities were suddenly stopped. However, choices made now and in the next few decades will determine the amount of additional future warming."
None of this will give those who choose to bury their heads in the sand much pause for thought, but what is of much more concern than the relative handful of climate change deniers is the inaction from global policy-makers, most of whom have gone on record as saying that climate change is a major threat to the planet and needs urgent action. It was discouraging that climate change was scarcely mentioned in the US presidential campaign. It will be interesting to see how much emphasis, if any, President Barack Obama places on the issue in his second inaugural address in Washington tomorrow. In his 2009 inaugural address, Mr Obama said: "With old friends and former foes, we will work tirelessly to ... roll back the spectre of a warming planet". Mr Obama has done far more than his predecessor, but he, along with other world leaders, have for the most part put the issue on the back burner. We have seen a global retreat from a determined effort to mitigate climate change. Alternative energy schemes get relatively little support compared to the astronomical sums earmarked for new fossil fuel projects that will require massive amounts of government-funded infrastructure.
Two examples are the trans-continental pipeline to carry oil from tar sands in Canada to the US Gulf Coast, despite the high carbon dioxide content of the tar sands oil, and the multinational rush to exploit oil under the Arctic Ocean despite the high risk of widespread environmental degradation in one of the few remaining pristine regions on the planet.
In Thailand, the government is compensating first-time car buyers in a deal that is great for the auto industry but horrible for air quality, not to mention traffic. This is all understandable to an extent. Oil is king and will be for some time, but small changes begun now to promote clean energy and energy efficiency can make a big difference over time in mitigating climate change, and who knows, someday Big Oil may lose its crown.
The bad news is that, dire as they are, even the worst-case scenarios presented in this report may be overly optimistic, as it is basically "a middle of the road" view of the evidence. Remember that Arctic ice has retreated at a much faster rate than all but the most pessimistic forecasters warned a few years ago. The good news is that, while climate change is happening now and will continue to worsen, mitigating global warming would not be nearly as expensive or as difficult as is often portrayed. There is no more time to waste.