Climate catastrophe: Arctic could be ice-free in summer A Leaked Draft Report Of The UN Reaffirms That Human-Induced Climate Change Is Heating Up Our Planet

Climate catastrophe: Arctic could be ice-free in summer

A Leaked Draft Report Of The UN Reaffirms That Human-Induced Climate Change Is Heating Up Our Planet

Nitin Sethi TNN

New Delhi: Of all the warnings about dramatic effects of climate change, a leaked draft UN report is the most vigorous in arguing that fears of an icefree Arctic Ocean in summer can become a reality if global temperature rises by more than 2 degree Celsius over current levels.
    The draft copy of the UN’s Intergovernmental Panel on Climate Change (IPCC) report says there is a 90-100% chance that the Arctic ice cover will continue to shrink through the 21st century with rising greenhouse gas (GHG) emissions.
    The potential reduction in Arctic ice, resultant rise in water levels and the possibility of new sea lanes accessing the frozen north of Russia, Japan and Scandinavian countries has engaged scientists for some time and the report provides more evidence that this could happen.
    But any economic benefits apart, changes in the polar ice cap can alter life on earth for the worse with more frequent hot spells unless the annual rate of greenhouse gas emissions is halted and even reversed.
    The scientific body predicts a global mean surface air temperature change for the period 2016–2035 compared to 1986–2005 could be in the range 0.4°C–1.0°C. The change, however, is likely on the lower range.
    Scientific evidence, the report claims, shows global combined land and ocean temperature data indicating an increase of about 0.8°C over 1901–2010 and about 0.5°C over the period 1979–2010. The inability of climate
negotiations to bridge the gaps between US, Europe and much of the developing world, including expanding economies such as China and India, makes the report’s forecasts even more worrisome.
    The draft report reaffirms that human-induced climate change is heating up the atmosphere leading to dramatic changes in global eco-systems.
    While there are natural factors at play, the human hand cannot be discounted and the report provides an update on a cut-off on greenhouse gas emissions to prevent irreversible climate change.
    The report, leaked by a known climate sceptic, is still in draft form and is to be finalised officially by October 2013.
    The draft can undergo moderation, but the science and evidence has been spelt out in some detail.
    The results of the report imply that the world cannot afford more infertile meetings like the recent one in Doha as there is an increasingly urgent need to set limits on cumulative GHG emissions and find a way to equitably share the finite carbon space.
    The Doha talks showed that countries continue to lack the economic appetite for imposing limits that involve large investments.
    The draft report says it is likely that hot spells will increase globally and the number of hot days will also go up over the next few decades.
    As these predictions are probabilistic in nature, scientists use the term “virtually certain” to imply a 99-100% probability of an event happening. Very likely refers to a 90-100% probability and likely 66-100% probability.
    This points to continued shrinking of glaciers, although there is less clarity on the rate of change. Again, the word ‘confidence’ is used to grade the degree of agreement and robustness of various published scientific data.
    The Greenland Ice Sheet has lost mass since the 1990s and the rate of loss has only increased. The Antarctic Ice Sheet is also losing mass at a high rate each year.
    The average decadal extent of Arctic sea ice has decreased in every season since satellite observations commenced in 1979 and its thickness and volume is in decline as well.
    Overall rainfall across the planet is also slated to rise and it is likely that the frequency and intensity of heavy precipitation events will increase, particularly at high latitudes.