Climate change has a surprising new follower: the president of the United States. The US government has been the biggest hurdle in climate change negotiations. Since discussions began on the issue in the early 1990s, the US has stymied all efforts towards an effective and fair deal. It has blocked action by arguing that countries like China and India must first do more. Worse, successive governments have even denied that the threat from a changing climate is real, let alone urgent. US President Barack Obama, who came to power in his first term with the promise to deal with climate change, was noticeably coy about the issue in recent years.
However, in May this year, the US government released its National Climate Assessment, which puts together carefully peer-reviewed scientific information on the impact of climate change in the US. It makes clear that even the US is not immune to the dangers of climate change. In fact, many trends are visible and the country is already hurting.
It is important to understand what this assessment concludes and why its findings are important for the rest of the world. One, it makes clear that the increase in temperature is now established; the rise in temperature is the highest in the poles, where snow and ice cover has decreased. As the atmosphere warms, it holds more water, which leads to more precipitation. Add to this the fact that the incidence of extreme heat and heavy precipitation is increasing - more heat and more rain. This makes for a deadly combination.
In the US, the incidence of heatwave has increased. In 2011 and 2012, the number of heatwaves was almost triple the long-term average. The assessment also finds that in areas where precipitation has not gone down, droughts occur. The reason is that higher temperatures lead to increased rates of evaporation and loss of soil moisture. In Texas in 2011 and then again in large parts of the Midwest in 2012, prolonged periods of high temperatures led to severe droughts.
In addition, now it does not just rain but pours. The heaviest rainfall events have become more frequent. Moreover, the amount of precipitation on the heavy rainfall days has also increased. Many parts of the country have already seen flooding, and the assessment is that these risks are significant in the future. This is combined with the fact that the intensity, frequency, duration and the number of strongest (category four and five) storms and hurricanes have increased since the 1980s, the period for which high-quality data are available.
Therefore, the news is not good for even a rich and temperate country like the US. For a long time, there was an unwritten agreement that climate change would benefit such countries. It was believed that they would become warmer, with the result that crop-growing periods would increase - which, in turn, would benefit their economies. The National Climate Assessment makes it clear that even if specific regions benefit from climate change, this will not be sufficient or durable. The net result will be economic disruption and disaster.
The other welcome change in the report is its clear assertion - something that needed to be stated bluntly to the American people - that climate change is caused by human activity. It cannot be dismissed any more as natural weather variability. Not only has there been an unprecedented build-up in the atmosphere of greenhouse gases resulting from the use of fossil fuels, fingerprinting studies can also attribute observed climate change to particular causes. Even as the stratosphere - the higher atmospheric layer - is cooling, the Earth's surface and lower atmosphere are warming. This is clearly the result of an increase in heat-trapping gases released from fossil fuels that countries burn to drive economic growth.
The message is clear: the time for complacency is over. The gases in the atmosphere have hit dangerous levels, which is hurting the US economy. The effort must include adapting, and building flood- and drought-resistant agriculture and infrastructure. However, this won't add up to much unless emissions from burning fossil fuels are cut fast and drastically.
This is where the report is the weakest. It says the current US contribution to annual global emissions is 18 per cent, but accepts that the country's contribution to cumulative emissions is much higher. Importantly, it also accepts that it is this stock of emissions that determines the extent of global climate change. Till now, the US position on historical emissions has been a stumbling block in negotiations.
The question is: what needs to be done? The US still does not have a plan to cut its emissions based on its contribution to the problem. Its stated voluntary target is to reduce emissions by 17 per cent over the 2005 levels. This is too little, too late - in fact, meaningless.
For the moment, we should accept that the elephant in the room has been acknowledged. This itself should lead to change.
sunita@cseindia.org
Twitter: @sunitanar
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