Why the world faces climate chaos
Last week the concentration of carbon dioxide in the atmosphere was reported to have passed 400 parts per million for the first time in 4.5 million years. It is also continuing to rise at a rate of about 2 ppm every year. On the present course, it could be 800 ppm by the end of the century. Thus, all the discussions of mitigating the risks of catastrophic climate change have turned out to be empty words.
His caveat is proper. Nonetheless, the greenhouse effect is basic science: it is why the earth has a more pleasant climate than the moon. CO2 is a known greenhouse gas. There are positive feedback effects from rising temperatures, via, for example, the quantity of water vapour in the atmosphere. In brief, humanity is conducting a huge, uncontrolled and almost certainly irreversible climate experiment with the only home it is likely to have. Moreover, if one judges by the basic science and the opinions of the vast majority of qualified scientists, risk of calamitous change is large.