Climate Change 2023: Synthesis Report

Global surface temperature in 2011-2020 rose 1.1°C above 1850-1900 levels. The temperature rise has been larger over land (around 1.59°C) than over oceans (around 0.88°C). The report also notes that the 50-years since 1970 saw the fastest temperature rise in history than any other 50-year period in the last 2000 years.

As much as 79 per cent of overall greenhouse gas (GHG) emissions in 2019 resulted from the energy, industry, transport and building sectors whereas 22 per cent were from agriculture, forestry and other land use.

Human-induced climate change is already influencing many extreme weather and climate events worldwide resulting in adverse effects on both nature and people. The rate of sea level increase has quickened over the last century. The rate of sea level rise was 1.3 mm per year between 1901 and 1971. It rose to 1.9 mm per year between 1971 and 2006; and to 3.7 mm per year between 2006 and 2018.

The report states that adaptation planning and implementation have advanced in all sectors and regions, showing documented benefits and varying levels of effectiveness. However, adaptation gaps remain and will expand if current implementation rates persist. The report adds that global financial flows for adaptation are inadequate at present, limiting efforts particularly in developing countries.

Since the fifth assessment report in 2014, policies and laws aimed at mitigation have steadily increased. However, the GHG emissions projected for 2030, based on nationally determined contributions (NDCs) announced by October 2021, suggest that warming is likely to surpass 1.5°C this century. Meanwhile, mitigation options have also become cheaper. Unit level costs of solar and wind energy have reduced by 85 and 55 per cent respectively between 2010 and 2019.

The report warns that global warming will continue to rise between 2021 and 2040 due to increased cumulative carbon dioxide emissions. Climatic and non-climatic risks will also increasingly interact, resulting in compound and cascading risks that will be more challenging to manage. Compound heatwaves and droughts are also predicted to become more frequent with multiple events across regions happening simultaneously.

Adaptation options that are currently feasible and effective will become more limited and less effective as warming intensifies. To avoid maladaptation, it is essential to engage in flexible, multi-sectoral, inclusive, long-term planning and implementation.

Achieving net zero CO2 emissions is essential to limit human-caused global warming. The total carbon emissions up to the point of reaching net zero and the greenhouse gas emission reductions in the current decade are crucial in determining whether warming can be restricted to 1.5°C or 2°C.

Surpassing warming beyond 1.5°C demands more extensive carbon removal, raising feasibility and sustainability concerns. Overshoot also brings adverse, possibly irreversible impacts and increased risks for both human and natural systems, worsening with the magnitude and duration of overshoot.

Effective climate action hinges on political commitment, coordinated governance, robust institutions, supportive policies, and enhanced access to finance and technology. The report says that scaling up regulatory and economic tools can drive substantial emissions cuts and climate resilience.

Finance, technology, and international collaboration are essential for accelerating climate action. To achieve climate goals, funding for both adaptation and mitigation must increase substantially.

Focus and Factoids by Sainka Walia.