No. 4 December 2021

The science of temperature overshoots

On behalf of CAN and AirClim, Climate Analytics has analysed the Impacts, Uncertainties and Implications for Near-Term Emissions Reductions if the planet overshoots a 1.5°C global temperature increase.

Climate science uses emission pathways to assess different trajectories towards limiting warming to specific warming levels, most commonly to below 1.5°C or 2°C. In recent years, so-called overshoot pathways have also increased in prominence. In overshoot pathways global mean temperatures temporarily exceed a specific target, such as 1.5°C, before bringing temperatures back down below the target.

https://climatenetwork.org/resource/the-science-of-temperature-overshoot...

Express your view on EU Air Quality

Have your say on the revision of the EU Ambient Air Quality Directives (2008/50/EC and 2004/107/EC). The European Green Deal announced this initiative under the umbrella of the Zero Pollution ambition for a toxic-free environment. Citizens and stakeholders are welcome to express their views. Public consultation is open until 16 December 2021.

Source: Air quality – revision of EU rules by European Commission, accessed October 2021 https://ec.europa.eu/info/law/better-regulation/have-your-say/initiative...

Vulnerable countries: high emitters must act

Some of the countries most vulnerable to climate breakdown have called on the UN and climate progressive countries to help them ensure high emitters upgrade their carbon targets, as called for at the COP26 in Glasgow. Countries such as Australia, which has refused to embrace strong carbon-cutting targets, would lose out economically. It would be “an uphill battle” to ensure adequate revisions to national carbon targets, and all those who want to see climate action must use the coming year to put pressure on the governments that had inadequate plans. At COP26, countries came forward with emissions-cutting targets, known as nationally determined contributions (NDCs), that would lead to an estimated 2.4°C of heating, far in excess of the 1.5°C set out in the Paris agreement. All countries agreed to return next year to COP27 in Egypt with reviewed targets. However, some countries are reluctant to strengthen their targets – Australia has already signalled its refusal, while the US and the EU have said their targets are good enough.

Source; Climate-vulnerable countries call for help forcing high emitters to act, The Guardian 18 November 2021

Climate Change threatens the capacity of oceans to store CO2

Rising temperatures could lead to substantial releases of carbon dioxide currently bound to the deep ocean floor, reports the BBC. This is extremely bad news, as the oceans have so far buffered some of the temperature rise that would otherwise have occurred because of the greenhouse effect of carbon dioxide. In fact, oceans take up about one third of the carbon dioxide released into the atmosphere. Part of the carbon is taken up by marine life and is eventually buried in the sea floor. According to the BBC, the amount of carbon stored in this way is counted in billions of tonnes. If carbon dioxide starts to be released from the sea floor, this would lead to additionally increased warming. Evidence for the release of carbon dioxide comes from experimental work within the iAtlantic research programme. The work specifically focused on the deep ocean, which covers more than 60 per cent of our globe. For the experiments, sediment (in essence, material that constitutes the sea floor) was brought from the abyss to the laboratory, and studied under temperatures that are predicted for the end of this century. Reportedly, temperature rise increases the release of carbon dioxide from these deep-sea sediments.

Source: Gills, V. “Ocean’s climate change ‘buffer’ role under threat”, https://www.bbc.com/news/science-environment-59214866