Humans are warming the planet. Climate scientists are 95 percent sure of this - as sure as they are that cigarette smoking causes cancer. That's one takeaway from the big new climate report by the Intergovernmental Panel on Climate Change, which began rolling out Friday.
The major report synthesizes the vast array of climate science research out there. Humans have pushed temperatures higher by burning fossil fuels, clearing forests, and other activities. If we keep emitting greenhouse gases, that will lead to more ice melt and higher sea levels in the decades ahead.
None of this is too surprising. Climate scientists have known that humans are warming the planet for many years - their confidence has gone up, but the conclusion has stayed the same.
Even so, it's worth reading through the summary of the IPCC report to see what else the climate panel has to say. There are some new details here, including the critical point that humans will have to keep the vast majority of their fossil-fuel reserves in the ground if we want to keep global warming below 2ºC, the level deemed "dangerous" by world leaders.
1) Humans are in control of how much the planet will heat up in the decades ahead. We can choose 1ºC (or less) of global warming. Or we can choose a drastic 4ºC.
This may seem like an obvious point, but it's worth dissecting. The IPCC report notes that there's typically a fair bit of natural variability in the climate system, thanks to volcanic eruptions, solar cycles, and various ocean processes. As a result, we're likely to see some fluctuations in global temperatures for years to come - the recent slowdownis a perfect example - even as the long-term trend is upward.
David Fuller's view I have had a good look at the official
summary of the IPCC report released today, and you will not be surprised
to hear that it is an uncomfortable read. However, its' 'solution', and apparently
only for part of the problem, at least in terms of what IPCC has said so far,
is to significantly reduce the use of fossil fuels.
We already know that not a single developed country has had much 'success' in doing this, and the cost has been uncompetitively high fuel costs and a risk of future blackouts, as we face here in the UK. More importantly, developing countries and not least those with high populations have made it very clear that they are not going to reduce their consumption of fossil fuels. Their priority is GDP growth because they know that higher fuel costs would be devastating for their numerous citizens who still live in conditions of severe poverty.
We can reduce CO2 emissions with natural gas and the new generation of nuclear energy. Simultaneously, we can develop less costly technologies for capturing CO2 when using fossil fuels. Additionally, it should not be beyond the ability of today's rapidly developing technologies to suck CO2 emissions out of the atmosphere.
(See also: Four Numbers Say Wind and Solar Can't Save Climate, posted on 23rd September, and This Car Runs on Gas Made Out of Thin Air, posted on 6th September 2013)