This graphic give a pretty good summary of the relative impact: https://3c1703fe8d.site.internapcdn.net/newman/gfx/news/hire...
There are parts of the world (for example, Africa) where population has been increasing ridiculously fast for decades and the estimates are that this will continue. A lot of this is thanks to the financial support from the West. When there's news that the population of Japan is decreasing people talk about it as if it's a catastrophe. But Japan is very densely populated right now and I think they'll be fine either way (maybe some short term economic struggles, but they won't go extinct).
These topics can be politically taboo, but they shouldn't be. These issues are too important and long term effects can be catastrophic for the environment and the general quality of life on Earth.
Africa is big, so it's a very coarse way of narrowing down a location. Population pressure is a multiplier, so people in poor countries with few cars and a diet that does not depend on cross-country transport of food have a smaller impact on environment than fewer people accustomed to a more expensive life style.
> When there's news that the population of Japan is decreasing people talk about it as if it's a catastrophe.
An aging or decreasing population can be a catastrophe, but not because of environmental effects; the concerns are of a social nature, as a shrinking population usually means a reduction in essential services. The one child policy that was active for years in China has left a characteristic mark on the demographics, leading to a small population of young people supporting a large population of old people.
There is no meaningful "average" child, or average lifestyle, to base the last column on.
No, I'm not implying that we shouldn't decrease population, just pointing out energy inequality.
Also the chart severely underestimate the impact of diet.
At least in my plug-in hybrid I get statistics on that. I have driven it 80% on electricity with average fuel consumption of 2.0 l/100km the 16 months I have owned it, that include 2 longer trips of 700km with average fuel consumption of 4.0 l/100km and some charging problems last winter. The car have 200hp, so would have been a lot more if not hybrid.
(I also find the argument hard to believe, but I'd be interested in seeing a proper comparison)
You would not be looking at efficiency from a energy/$ perspective, which is what industry power generators care about, but rather energy/ton of CO2, which they rarely care about.
At least with the Prius-style hybrids, though, regenerative braking isn't the only advantage:
* The engine is an Atkinson cycle, which has better thermal efficiency than a typical Otto cycle engine.
* The electric motor is providing torque off the line, so there is no need for a torque converter (which reduces efficiency).
* The engine can be completely shut off when cruising at low speeds.
* The power split device (PSD) is more reliable than a traditional transmission, reducing maintenance costs over the lifetime of the vehicle. (it is much less labor intensive to replace the battery than to service the transmission)
The advantages add up when driving around town, but at highway speeds, a 3-cylinder or small 4-cylinder non-hybrid will often have better gas mileage.
While I agree with your sentiment, I think it's dishonest to not mention the fact that diesels were absolutely dominating until the rules were changed in hybrids' favour a few years back.
The goal of combating climate change is to make the planet more liveable. You don't achieve that by not living.
It's not some moral game of attribution of blame, it's just maths. Fewer people produce less CO2.
That, or we end as species. Guess what? Worst case of global warming, mankind extermination. "Best" case, also mankind extermination.
Talk about premature optimisation!
Further to that, I'm not sure it's a good idea anyway in many cases if you're worried about sustainability of the human race and our current lives - if we all stopped having children, society would pretty much collapse. Who's going to look after us when we're old? Clearly we don't all need to have 12 children, but 0 won't work either.
If you are unhappy with the level of education of the public, then try to work on that instead of feeling encouraged to spread your superior genes.
I recommend Carl Zimmer's latest book "She Has Her Mother's Laugh" for a look at the past and the present through the prism of heredity.