July 2024: While some of the pages listed below haven’t been updated in a couple of years, they still contain useful information. Hopefully they’ll be updated soon.
An Existential Threat
This 4 part series explains the threat to the existence of civilisation and life on Earth due to the degradation caused by our greenhouse gas emissions.
Part 1
Sea level rise due to ice sheet loss.
Part 2
Rapidly melting Arctic sea ice is triggering a fast amplifying feedback that drives further warming. A striking consequence is the global trend of glacier retreat.
Part 3
Climate change impacts on human health and wellbeing.
Part 4
Climate change impacts on biodiversity.
Responsibilities
Those countries most to blame for climate change, and therefore should be leading wth radical emission reductions, are those that have the highest cumulative-per-capita emissions: the U.S., U.K., Germany, Canada, Russia, Australia and Japan.
The UNFCCC
CO₂ emissions from fossil fuels and industry in 2020 increased 90% since 1980, when the first joint scientific meeting about CO₂ was held, and 57% since the first ‘international climate summit’ (COP1) in 1995.
1.5˚C
Future emission pathways that temporarily overshoot 1.5˚C prescribe global CO₂ emission reductions of a rate similar to that in Russia following the collapse of the Soviet Union, and in France and Sweden after the commissioning of large shares of nuclear energy. In addition to this, these pathways also prescribe a new carbon sink on the scale of the global ocean carbon sink, because we don’t expect to be able to fully decarbonise our civilisation, and we have been slow to act.
Our Current Path
Every year energy use increases, and most of the increases come from fossil fuels. Current policies presently in place around the world are projected to result in about 3.3°C warming above pre-industrial levels.
Changing Temperature Extremes
Global warming is often described and summarised as a change of global mean surface temperature (e.g. the ‘1.5˚C’ temperature limit that formed part of the ‘Paris Agreement’). This page describes the often overlooked consequential changes to seasonal extremes.
350 ppm
Dr Hansen prescribes changes needed to reduce atmospheric CO₂ to less than 350ppm, in order to limit global temperature close to the Holocene range.