DEBATE @ THE HINDU The lag between carbon emissions and warming suggests that the earth will get unavoidably warmer, not cooler
The Russian scientists quoted in the article in The Hindu (Op-Ed, “Down to minus 45,” April 22, 2013) make three claims that are either partial truths or assertions with little basis in fact that: there will have been no global warming since 1998, climate moves in natural cycles of warmer and colder and early signs of cooling are visible, and, future generations will face temperatures several degrees lower than those of today.
The year 1998 happened to have been an unusually warm one because the strongest El Niño of the 20th century occurred in 1997-98. To set 1998 as a benchmark to gauge subsequent temperature trends is to wilfully skew the comparison. To give a parallel, it’s like setting the 2002 drought year as the benchmark for subsequent measurement of rainfall and foodgrains yields in India. Nine of the 10 warmest years in NASA’s database since 1880 — the sole exception was 1998 — occurred subsequently, in the first decade of the 21st century. In India too, the trend is one of warming. In 2012, the India Meteorological Department (IMD) issued a table comparing temperatures for the first decade of this century with the baseline period 1960-1990. Average temperatures in India had risen, from 24.87°C to 25.51°C, by then. What’s more, while there was expected fluctuation between years, not a single year between 2001 and 2010 was colder than the 1960-1990 average: the coldest year (2008) was 0.38°C warmer while the warmest year was 0.93°C warmer (IMD, “Annual Climate Summary of India During 2011,” January 13, 2012).
The recent cold winter may have catalysed renewed debate about global warming. The unusually cold winters of 2009 and 2010 at mid-latitudes were due to something quite prosaic — incoming cold air from the Arctic (James Hansen, et al, “Global Temperatures in 2011, Trends and Prospects,” GISS/NASA, January 2012). Have we though, as is claimed by Professor Kotlyakov in the piece, entered a natural phase of cooling whose early signs are visible? There’s no elaboration about what that natural phase might be. The Earth goes through several cycles, ranging from a few years to millennia, but none has been observed in recent years, other than the usual 11-12 year cycle of solar irradiance. If anything, we have in recent years benefited from a cool phase of the Sun. But even in this, the Sun’s effect, i.e. the difference between the solar minimum and maximum over the 11-year period (a difference of 0.25 watts per square metre of the Earth), is masked by potential effects of greenhouse gases emitted in this period (0.58 watts/m).
A slowdown in warming at the surface and top layer of the oceans in recent years may have fed scepticism. But this was puzzling for some, for there has been more energy trapped by greenhouse gases than this recent slowing in surface warming warrants. It now turns out it was misleading. A new paper reveals that changes in surface winds may be taking this missing excess heat into the deeper oceans, causing “unprecedented” warming of those waters. “In the last decade, about 30% of the warming has occurred below 700 metres, contributing significantly to an acceleration of the warming trend.” (Magdalena Balmaseda, et al, “Distinctive Climate Signals in Reanalysis of Global Ocean Heat Content,” Geophysical Research Letters, March 13, 2013, doi: 10.1002/grl.50382). The slowing is on the surface, literally and metaphorically.
Dr. Nagovitsyn then goes on to make the outrageous claim that future “generations will have to grapple with temperatures several degrees lower than those we have today.” Again, an assertion with little elaboration; given that the difference in average temperatures between now and the peak of the last Ice Age 20,000 years ago was 6°C, what does he mean by “several degrees lower”? If anything, the lag between carbon emissions and warming suggests that we will get unavoidably warmer, not cooler. The Intergovernmental Panel on Climate Change’s 2007 AR4 report said the “commitments to climate change … are expected to be about 0.5°-0.6°C, mostly within the coming century.” And there are those who suggest that this “committed warming” may well be a lot more.
These outrageous assertions run against the laws of established science, which have conclusively shown that greenhouse gases trap radiation. More gases will cause more warming sooner rather than later and we are adding carbon to the atmosphere at least 10,000 times to the long-term natural rate of the carbon cycle.
These assertions also run against the laws of capitalism. Its inherent tendency is one of accumulation, profits and growth, the environment and people be damned. The roots of global warming — and many other ecological and other ills thrust on the poor everywhere — lie in this systemic economic logic. The oceans and the atmosphere are just capitalism’s largest waste dumps. Notwithstanding the energising political developments in Latin America and elsewhere, we are hardly being able to undermine capitalism’s essential economic logic on the scale necessary. Nor will we be able to do so in the foreseeable future. Global warming, alas, is here to stay, the new normal. Unsubstantiated assertions are neither a good way to tackle it nor sound bases for healthy debate.
(Nagraj Adve is an activist based in Delhi, who works on issues related to global warming. E-mail: email@example.com)