UN Secretary-General Antonio Guterres and countless authorities around the world have lined up with the IPCC to confirm that global temperatures have already increased 1.09°C compared to pre-industrial temperatures – an increase more significant than anything that has occurred for more than 100,00 years. And that over the next 20 years, average global temperatures are expected to reach or exceed 1.5°C of warming.
The following information is from IPCC reports and press releases and is intentionally shared as published.
Many characteristics of climate change directly depend on the level of global warming, but what people experience is often very different to the global average. For example, warming over land is larger than the global average, and it is more than twice as high in the Arctic.
“CLIMATE CHANGE IS ALREADY AFFECTING EVERY REGION ON EARTH, IN MULTIPLE WAYS. THE CHANGES WE EXPERIENCE WILL INCREASE WITH ADDITIONAL WARMING,” SAID IPCC WORKING GROUP I CO-CHAIR PANMAO ZHAI.
The report projects that in the coming decades climate changes will increase in all regions. For 1.5°C of global warming, there will be increasing heat waves, longer warm seasons and shorter cold seasons. At 2°C of global warming, heat extremes would more often reach critical tolerance thresholds for agriculture and health, the report shows.
But it is not just about temperature. Climate change is bringing multiple different changes in different regions – which will all increase with further warming. These include changes to wetness and dryness, to winds, snow and ice, coastal areas and oceans. For example:
The IPCC have published an interactive map which allows you to examine specific geographies and the sobering news for Australia is that average temperatures have already risen 1.4°C and with it the reminder that we can expect higher heat extremes and an increase to the frequency and severity of both extreme fire events and heavy rainfall and river flooding. Below is a transcript of the headline statements.
When the IPCC and other bodies publish these reports, they make the full report and various summary data available to policymakers - ie: government. This headline information below is exactly as printed for policymakers.
A.1 It is unequivocal that human influence has warmed the atmosphere, ocean and land. Widespread and rapid changes in the atmosphere, ocean, cryosphere and biosphere have occurred.
A.2 The scale of recent changes across the climate system as a whole and the present state of many aspects of the climate system are unprecedented over many centuries to many thousands of years.
A.3 Human-induced climate change is already affecting many weather and climate extremes in every region across the globe. Evidence of observed changes in extremes such as heatwaves, heavy precipitation, droughts, and tropical cyclones, and, in particular, their attribution to human influence, has strengthened since the Fifth Assessment Report.
A.4 Improved knowledge of climate processes, paleoclimate evidence and the response of the climate system to increasing radiative forcing gives a best estimate of equilibrium climate sensitivity of 3°C, with a narrower range compared to AR5.
B.1 Global surface temperature will continue to increase until at least the mid-century under all emissions scenarios considered. Global warming of 1.5°C and 2°C will be exceeded during the 21st century unless deep reductions in carbon dioxide (CO2) and other greenhouse gas emissions occur in the coming decades.
B.2 Many changes in the climate system become larger in direct relation to increasing global warming. They include increases in the frequency and intensity of hot extremes, marine heatwaves, and heavy precipitation, agricultural and ecological droughts in some regions, and proportion of intense tropical cyclones, as well as reductions in Arctic sea ice, snow cover and permafrost.
B.3 Continued global warming is projected to further intensify the global water cycle, including its variability, global monsoon precipitation and the severity of wet and dry events.
B.4 Under scenarios with increasing CO2 emissions, the ocean and land carbon sinks are projected to be less effective at slowing the accumulation of CO2 in the atmosphere.
B.5 Many changes due to past and future greenhouse gas emissions are irreversible for centuries to millennia, especially changes in the ocean, ice sheets and global sea level.
C.1 Natural drivers and internal variability will modulate human-caused changes, especially at regional scales and in the near term, with little effect on centennial global warming. These modulations are important to consider in planning for the full range of possible changes.
C.2 With further global warming, every region is projected to increasingly experience concurrent and multiple changes in climatic impact-drivers. Changes in several climatic impact-drivers would be more widespread at 2°C compared to 1.5°C global warming and even more widespread and/or pronounced for higher warming levels.
C.3 Low-likelihood outcomes, such as ice sheet collapse, abrupt ocean circulation changes, some compound extreme events and warming substantially larger than the assessed very likely range of future warming cannot be ruled out and are part of risk assessment.
D.1 From a physical science perspective, limiting human-induced global warming to a specific level requires limiting cumulative CO2 emissions, reaching at least net zero CO2 emissions, along with strong reductions in other greenhouse gas emissions. Strong, rapid and sustained reductions in CH4 emissions would also limit the warming effect resulting from declining aerosol pollution and would improve air quality.
D.2 Scenarios with low or very low greenhouse gas (GHG) emissions (SSP1-1.9 and SSP1-2.6) lead within years to discernible effects on greenhouse gas and aerosol concentrations, and air quality, relative to high and very high GHG emissions scenarios (SSP3-7.0 or SSP5-8.5). Under these contrasting scenarios, discernible differences in trends of global surface temperature would begin to emerge from natural variability within around 20 years, and over longer time periods for many other climatic impact-drivers (high confidence).
I just want to confirm that these reports from the IPCC are both available to everyone and exactly what is provided to our governments. These are links to the 42 page policymaker summary Climate Change 2021: The Physical Science Basis - Summary for Policymakers. And to the 3949 page full report Climate Change 2021: The Physical Science Basis.
In addition to the report, the IPCC has released an interactive atlas showing how climate change will affect every single world region under different emissions scenarios. Detailed data sets are available to anyone.
Image: IPCC 2021 Report - Changing by the artist Alisa Singer: "As we witness our planet transforming around us we watch, listen, measure … respond."