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focused on single extreme events and
their attribution, leaving the evolution
and characteristics of compound
extreme weather events in the mist.
The new report also brings up the
discussion on ‘tipping points’ in the
climate system. We have come to the
understanding that despite a small
probability, once the tipping points are
breached, there could be disruptive
consequences.
Last but not least, it further confirms
– with scientific evidence – that we must
achieve net zero emissions around
2050, in order to keep the climate
targets made in the Paris Agreement.

LINCOLN MUNIZ ALVES
CLIMATE PROTESTORS Research Scientist (WG1 Atlas lead author)
Instituto Nacional de Pesquisas Espaciais,
Furthermore, as part of the AR6, all scenario expected to limit warming to São Paulo
three working groups have adopted less than 2°C. The recent climate extremes in many
a common risk framework. The WG1 Other outcomes such as ice sheet parts of the world underscore the need
contribution to this risk assessment instability processes leading to for robust climate policy. So, I think the
is the climatic impact drivers and potentially amplified sea level rise are Interactive Atlas is a hugely valuable
the assessment of the likelihood of associated with deep uncertainty and resource for that, where you can explore
their changes. Both the summary for their likelihood is not well known. possible climate futures for your region
policymakers and the underlying Nevertheless, these outcomes are an at different levels of warming.
chapters describe low-likelihood, high- integral part of risk assessment given
impact outcomes (LLHI) as outcomes their potential high impacts on society DR JOERI ROGELJ
whose probability of occurrence is low and ecosystems. Director of Research (AR6 WG1
but whose potential impacts on society Chapter 5 lead author)
and ecosystems are high. DR AIDA DIONGUE-NIANG Grantham Institute for Climate Change,
Low-likelihood high impact Researcher Imperial College London
events are important to understand Global Green Growth Institute, Senegal There is one key take-away from the
and communicate as they form an I appreciate the fact that the report AR6 WG1 and that is: we know enough.
integral part of a comprehensive addresses the greenhouse gas In the strongest terms ever, the IPCC
risk assessment. The importance of emissions responsible for global establishes that global temperature
communicating low-likelihood high- warming and also air pollutant has increased, oceans have warmed,
impact events has been strongly stated emissions, with a focus on reducing glaciers are retreating, extreme weather
in many government review comments, methane emissions to improve air is getting more intense and global sea
they are introduced in detail in chapter quality and partially offset the warming level is rising. Human activity is behind
1 and further developed in chapter 12, induced by aerosol reduction. this – unequivocally. These changes
and are also an important aspect of the I see this as an important synergy, are exceptional and unprecedented in
‘handshake’ with WG2. especially in developing countries human history, many are irreversible
which today have low greenhouse on human timescales. The latest WG1
DR ERICH FISCHER gas emissions but high rates of report also tells us that we understand
Senior Scientist and Lecturer urbanisation and population growth all the puzzle pieces we need to halt
(AR6 WG1 lead author) and significant air quality problems. this warming: achieving net zero
ETH Zurich CO₂ stabilises warming; net zero
Previous IPCC reports have been PROF TONG JIANG greenhouse gas emissions results in a
criticised for being too narrowly Dean at the Institute for Disaster Risk peak followed by a gradual reversal of it;
focused on likely outcomes. We would Management (WG2 review editor) and estimates of the remaining carbon
never do this when buying property Nanjing University of Information Science budget are clear, robust, and so small
insurance – where we are interested in and Technology they leave no time to loiter.
the one per cent, 0.1 per cent or even The new report adopts the latest We know enough, we have enough
lower likelihood outcomes that cause ‘shared socio-economic pathway’ (SSP) science. Let’s get on with working
the largest damage. scenarios. It also forms a closed loop on towards addressing this challenge that
Therefore, it is a major advance that climate science, covering the science, will define humanity over the next
IPCC AR6 specifically assessed such low- impacts, vulnerability and mitigation of decades and centuries.
likelihood high-impact outcomes. This climate change.
includes the occurrence of unprecedented Furthermore, AR6 carries out Article first published by Carbon Brief,
or novel combinations of compound comprehensive risk analysis on a UK-based website covering the latest
events, or levels of global warming that compound extreme weather events. developments in climate science, climate
substantially exceed the very likely range, This represents a major step forward policy and energy policy. For more
e.g., 2.5°C global warming in an emission since the AR5 report, which mainly information, visit www.carbonbrief.org.

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