A Chronological Narrative By Girija Ramanathan who lived through it all
Until 1975, the world thought Carbon dioxide from fossil fuels was the only manmade gas causing global warming. In 1975 Ram discovered the greenhouse effect of Chlorofluorocarbons (CFCs). His paper in the journal, Science stated that Chlorofluorocarbons, found only in trace amounts in the atmosphere, was a potent greenhouse gas. He showed one molecule of Chlorofluorocarbons warms the planet as much as 10,000 molecules of CO2. This finding opened the door for the discovery of other manmade trace gases like methane, nitrous oxide and ozone. He also showed in 1976 stratospheric ozone depletion by manmade activites can lead to global cooling. These findings opened the door for cloud-chemistry-climate interactions. It is after the publication of this paper that scientists like Crutzen (Nobelist), Cicerone (Former chancellor of UC Irvine) etc. got into the climate game.
From 1976-86 Ram was at NCAR delving into climate modeling. Collaborating with three other scientists he built the first version of a climate model, which is now world famously called CCSM (Community climate simulation model). During this period, he and other scientists from NASA proposed to send a earth orbiting satellite to collect radiative climate data (ERBE - Earth radiation budget experiment). Helped design instruments to be loaded on the ERBE satellite. After the data started streaming into NASA computer, he learned to analyze the mountains and mountains of data. He wrote his paper on super greenhouse effect of water vapor in the Pacific ocean. He also led a study with the ERBE data that showed that the background clouds had a global cooling effect.
Further analysis suggested that there was a cloud thermostat, which controlled the temperature in the pacific warm pool not to exceed a certain temperature threshold.
This finding lead to the CEPEX.
Analysis of the data from CEPEX lead to his famous paper subtitled "Missing Physics". This paper raised the possibility that the solar radiation coming into the earth is substantially less than model predictions. He deduced there was some constituent or physics, unknown to models, in the atmosphere was absorbing sunlight.
In 1997 Ram lead the INDOEX experiment of over 200 scientists from around the world including India to find this anomalous absorption.
The rest is history.
During the campaign, on a C-120 plane, he and a few other scientists saw the brown haze over all of India and China. Ram and his colleagues saw the significance of this and named this Asian Brown Cloud (ABC), changed subsequently to Atmospheric Brown Clouds (ABC).. Ram along with his post-doc wrote a seminal paper stating that black carbon was a major component of the haze over Asia, and a potent absorber of sunlight the so-called missing physics in the CEPEX data. This lead to the next phase - ABC project funded by UNEP. This project, with China, India, Europe and USA as partners, was lead by Ram and Crutzen and observation towers were set up in countries like China, Korea, Japan, Nepal etc.
Ram's research lead him to the conclusion that black carbon (also known as soot) was the second largest global warmer and he showed it heated the air above the Himalayan/ Tibetan glaciers, settled on ice sheets and warmed then thereby melting the glaciers. He also discovered that the Indian monsoons were being disrupted because of the brown clouds pollution. At this time he teamed up with two economists at UCSD to analyze rice harvest in India and concluded that indeed the monsoons were delayed or slowing down thereby affecting the rice harvest.
He then started project Surya with TERI(an Indian NGO) and Nithya (our daughter) to conduct a scientific experiment using cell phones and ground based instruments and satellite data, to see how much of the black carbon in the air was due to inefficient mud stoves. He also wanted to document the deaths and ill effects of mud stoves on the health of women and children. About 4 million die worldwide due to smoke inhalation. They then distributed efficient cooks stoves (different models) and collected data again.
After the pilot phase was completed they concluded that less black carbon escaped into the atmosphere, thereby contributing less to the haze.
He has written many journals and papers including Nature, Foreign Affairs, op-eds in the NY Times, Washington Post, etc. to push the idea to policy folks, to impress upon them that short-lived climate pollutants (SLCPs) - HFCs, Methane, Ozone and Black Carbon - must be cut and there are already technologies to do it effectively and simply.
Note: HFCs, which were invented by DuPont after CFCs were banned as propellants and coolants in refrigeration, are also a potent greenhouse gas. One molecule of HFCs is equivalent to 1000 molecules of CO2.
The difference between CO2 and SLCPs is that CO2, once it is in the atmosphere it could stay there for a century or more. On the other hand, SLCPs, once they are removed from the atmosphere, their ill effect goes away as well. Thus reducing SLCPs can get quick relief from climate change. He was vice-chair of the UNEP report on SLCPs.
Ram's paper in Foreign Affairs and the UNEP report lead to the formation of Climate and clean air coalition (CCAC) by Hillary Clinton and others, which is trying to bring all the nations to agree to cutting SLCPs in the near future, and help in removing them from the atmosphere. 30 nations now have joined the coalition.
He continues to push on both fronts - science and policy. He, this year, showed how reducing black carbon and other SLCPs can reduce sea level rise, which is one of the biggest threats to San Diego and other coastal cities.