So much news about climate change has come out in the last few weeks, it is hard to keep track of it all. Here is a summary of all the new findings and what they mean.
Levels of greenhouse gases in the atmosphere have reached a new record, according to the World Meteorological Organization. The concentration of carbon dioxide hit 405.5 parts per million in 2017, "up from 403.3 ppm in 2016 and 400.1 ppm in 2015". This is exactly what we could expect as we haven't stopped releasing them.
“The last time the Earth experienced a comparable concentration of CO2 was 3-5 million years ago, when the temperature was 2-3°C warmer and sea level was 10-20 meters higher than now,” said WMO Secretary-General Petteri Taalas.
Not only have we not stopped releasing greenhouse gases, we are putting them out faster than before. According to the UN Environment Programme, CO2 emissions rose in 2017, for the first time in four years. That is disappointing, because the pause in emissions growth happened while the global economy kept growing, suggesting that we were starting to "decouple" economic growth from greenhouse gas emissions. Evidently, we weren't.
One contributor will be the rise in Amazon deforestation, which hit its highest level in a decade between August 2017 and July 2018. The rate of Amazon deforestation is still far slower than it was in the 1980s and 1990s, but it is concerning that it has started accelerating again.
The rise in emissions was included in UNEP's "emissions gap" report, which comes out every year. The report looks at how much we need to cut our emissions to limit climate change to the "safe" level of 2°C - and then how big the gap is between the promises made so far and what's actually necessary. "This year's report records the largest gap yet between where we are and where we need to be," wrote Matt McGrath of BBC News. To limit warming to 2°C, nations will need to triple their efforts.
The consequences of the warming climate look set to be severe. The UK's Met Office released its first big update on climate change in a decade, the UK Climate Projections 2018. It warns that UK summers could be 5.4°C warmer by 2070 than they were in 1981-2000. That means the chances of another summer as warm as 2018's (which was, by British standards, ludicrously hot and the joint hottest on record) will be about 50 per cent by 2050.
That's in line with trends so far. According to another Met Office report, "the hottest day of each year over the most recent decade (2008-2017) in the UK has been on average 0.8°C warmer than the hottest day of each year over the period 1961-1990."
The US government has released its Fourth National Climate Assessment, exploring the risks to American society. "With continued growth in emissions at historic rates, annual losses in some economic sectors are projected to reach hundreds of billions of dollars by the end of the century—more than the current gross domestic product (GDP) of many U.S. states," the report said. However, US President Donald Trump dismissed the report, saying "I don't believe it".
The warming will be bad for our health, according to a new study in The Lancet. Researchers found that the proportion of the global population vulnerable to heat-related death and disease is on the rise. The main cause is rising temperatures, but the growing number of people living in cities (which tend to be warmer than the countryside), and of older people, are also factors. In 2017, 157 million vulnerable people were exposed to heatwaves globally, and 153 billion hours of labour were lost due to heat exposure.
The Arctic ecosystem is also being drastically changed, because it is warming faster than the rest of the planet and the crucial sea ice is retreating. The UK Parliament's Environmental Audit Committee has published a report entitled The Changing Arctic, which summarises what is happening. "The Arctic is undergoing profound environmental change from warming surface and ocean temperatures," the committee writes. "Multiyear sea ice has been reducing for decades, and melting has accelerated since the early 2000s. It is now at its lowest level since records began and the Arctic Ocean may be ice free in the summer as soon as the 2050s, unless emissions are reduced. The acidification and Atlantification of the Arctic Ocean are causes for significant concern as they threaten marine wildlife and global climate patterns. Additionally, one trillion plastic particles frozen into Arctic sea ice could be released into the ocean through accelerated melting."
Now for the good news. Every tonne of carbon dioxide we refrain from emitting will mean slightly less warming, slightly gentler effects. As I've said before, forget about claims like "only 12 years and then it's too late" and focus on the simple fact that every move we make to reduce climate change will be beneficial, both to our health and to the economy.
The UK could become carbon-neutral by 2045, meaning any carbon dioxide it emitted would be balanced by carbon dioxide that was newly locked up, for instance in newly-planted trees, according to a recent WWF report. And in fact the European Union has announced that it will try to become climate-neutral by 2050. That will be a challenge, but the very fact the EU is shooting for it is good news. The EU may also try to clamp down on emissions from aviation, which are particularly tricky to cut.
What's more, the UK seems to have finally bitten the bullet on carbon capture and storage (CCS). This is a technology to trap carbon dioxide as it escapes from power plants and other sources, then bury it underground in rock formations that will lock it away for millennia. The UK has dithered about implementing CCS for years, and in 2015 the government abandoned a £1 billion competition intended to develop the technology. But now, ahead of a summit in Edinburgh, ministers have promised to set up a working CCS plant at a site in Scotland.
None of this is enough to limit warming to 2°C, let alone the more ambitious target of 1.5°C. But they are positive steps.
Date: Nov 29, 2018