How much can we trust the IPCC?

Climate change driven catastrophes on the rise

2020/2021 featured many climate related catastrophes such as wildfires, tropical cyclones and floods. Advances in the science of detection and attribution of climate change means these events are increasingly being linked to warming that has already elapsed.

IPCC climate change assessments

Consolidating more than 15,000 peer reviewed papers and a taskforce of more than 200 climate scientists, the Intergovernmental Panel on Climate Change (IPCC) assessment report represents the current best view of climate science. Despite this being the 6th report since 1990, our knowledge of the climate system is far from complete, and the illustration below shows that IPCC projections have been changing with each successive assessment.

Change in global mean temperature at year 2100 under best-case and Business As Usual (BAU) scenarios

Global mean temperature +1.1°C relative to 1850-1900

The seemingly small shifts in global mean temperature masks the disproportionate impact of climate extremes. Hence, when the IPCC updated their worst case projections from 3-3.5 deg to 4-4.5 deg, this is highly significant. For example, in a world that has already warmed by about 1.1 deg, extreme event attribution studies show that the recent Lytton record temperatures  and ensuing wildfires are 150x more likely.

Language used across these assessments

The language and tone used in these assessments have also been changing over time, with increasing urgency and certainty in future projections.

What does the future hold?

The extreme events and biodiversity loss experienced to date are linked to a global average temperature increase of just over 1 deg from pre-industrial levels. If we continue on current emissions trajectory, as the chart below shows – today's extremes could be tomorrow's normal conditions. As such, there is a compelling economic and moral case to reduce emissions as rapidly as possible while ensuring a sustainable transition plan for the impacted industries.

This article was first published on Insights Artist.


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