As pointed out in email

[james_davis_nicoll]

India’s declining fertility rate, now only slightly higher than that of the United States, is part of a global trend of lower population growth. Yet the media and many educated Americans have entirely missed this major development, instead sticking to erroneous perceptions about inexorable global population growth that continue to fuel panicked rhetoric about everything from environmental degradation and immigration to food and resource scarcity.

In a recent exercise, most of my students believed that India’s total fertility rate (TFR) was twice that of the United States. Many of my colleagues believed the same. In actuality, it is only 2.5, barely above the estimated U.S. rate of 2.1 in 2011, and essentially the replacement level.

Comments

[mishalak.livejournal.com]

Yes. I see hints of green like a garden after a hard winter.

For example US greenhouse gas emissions have been dropping for the last seven years, with it now being below 1995 levels despite there being more Americans and a larger economy. To be totally fair this is due in part to a lousy economy, but that is not the whole story. It is also due to the massive increase in natural gas use, to the point where it is displacing the much worse coal. I think even if the economy had been rescued by a Keynesian style stimulus that we would still be below peak emissions of 2005.

Essentially flat emissions by the worst per capita polluter are emphatically not good enough, but I think this points to the potential for real improvements in the future when all the potentially useful innovations are considered. I think there will be significant problems due to climate change we have already locked in and that they will also be overcome through trade and planning while the world transitions to a less carbon intensive economy. I predict that by 2050 that world carbon emissions will be lower than 1990 levels despite more of the world enjoying a middle class lifestyle.

I think climate change will be bad, but not disastrous.

[mindstalk.livejournal.com]

The US drop is pure luck, not policy. And while we're producing less CO2, what about the greenhouse burden of leaking methane?

[mmcirvin.livejournal.com]

Methane vs. CO2 is a two-sided coin: methane's a far worse greenhouse gas, but its dwell time in the atmosphere is far shorter, which means that there would be potential for faster recovery if we get off natural gas. (This is also part of the reason why the RealClimate folks generally argue that direct CO2 emissions are still the big thing to worry about, in response to people worrying about undersea methane hydrates.)

Still, I have my doubts that methane leaks are being adequately tracked.

[mishalak.livejournal.com]

As long as "fugitive methane emissions" are less than 3% of the total gas consumed then it still works out to be better than coal in terms of climate change potential. It is an issue that will need to be investigated and being better than coal is damning with faint praise, but still better.

I also think that the eventual drop in CO2 will be largely be about luck rather than policy. It will be about policy to the extent that there is a lot of research being done about efficiency and reducing the cost of lower carbon energy sources. However, a lot of it will be due to changes in the tastes of people that are underway. Instead of being overjoyed about a big new car many people now choose to spend money on a great computer. People in America are moving back to urban cores and choosing not to use cars for reasons other than being green. Plus there are the true believers who will keep looking for ways to make low carbon to work better than high carbon choices.

Methane/natural gas is not the only answer or one that will work forever, but right now it is part of reducing harm. Natural gas prices will eventually rise due to supply and at that point I think that even lower carbon choices will be more attractive than returning to coal or oil.