More From Dr. Ram on Climate Change

One of the elite scientists who advises the Holy Father as a member of the Pontifical Academy of Sciences is Dr. Veerabhadran (Ram) Ramanathan, professor of Atmospheric and Climate Sciences at the Scripps Institution of Oceanography, University of California at San Diego. Last week we began providing excerpts from a summary of a position paper written by Dr. “Ram,” entitled “The Two Worlds Approach to Mitigating Climate Change: The Top One Billion and the Bottom Three Billion.” We continue in this week’s Update.

What Is In Store For Us And For Generations To Be Born?

Ocean data have revealed that the added heat trapped by the thousand billion tons of greenhouse blanket has penetrated to a depth of more than 1000 meters in the ocean (Roemmich et al, 2015). The heat stored in the ocean will influence the climate for millennia even if we stop polluting the planet today. On the contrary we are continuing with the pollution at a faster rate. Roughly 50 billion tons of carbon dioxide and other warming gases are being added every year.  If the current rate of pollution continues, the planet can warm by as much as 2°C (3.5°F) by 2050 and as much as 4°C (7°F) by end of century (Schellnhuber, 2013). Such temperatures have not been witnessed in the last million years and the probability of tripping over many tipping points of the ecosystem is high (Schellnhuber, 2013). The damages to natural ecology, human health, water and food security due to drastic changes in iconic climate systems such as the Greenland glaciers, much of coastal systems, wetlands, Himalayan-Tibetan glaciers and rivers are incalculable. One major obstacle in estimating the damages is that the predictions of the future climate are subject to large uncertainty. The changes could be smaller than the predictions by a factor of 2 but could just as well be larger by a factor of 2. Already, the 4°C (7°F) warming predicted for 2100 would be unprecedented but if it is larger than the predicted by a factor of 2 or more (albeit a low probability event), it could be catastrophic. For example to find a past analogue to a world warmer than the present by 8°C (14°F), we have to go back more than 50 million years. Economists are beginning to recommend that such catastrophic warming, even if it is a low probability event, should govern our policy responses (Weitzman, 2011).

Who are Responsible?

Almost everyone and every industry are responsible for polluting the planet with carbon dioxide and numerous other greenhouse gases. But some are disproportionately more responsible than the others. As of today, about one billion people are consuming about 50% of the fossil fuel and contributing about 60% of the greenhouse gas pollution (Ramanathan, 2014). With the business as usual scenario, they will also be contributing about 60% to the increase in the emissions.  About 75% of this Top One Billion live in industrialized nations and the rest are distributed among the developing nations of the world (Chakravarty et al, 2012).  The bottom three billion, contribute only about 5% to the emissions … The balance of 25% of the emissions is due to the middle and low-income population of about three billion.

 

Posted: July 2, 2015

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