14 July, 2022

Uncertainty in near-term temperature evolution must not obscure assessments of climate mitigation benefits

Authors

Alexandrine Lanson, Peter Pfleiderer, Flavio Lehner, Carl-Friedrich Schleussner

This study builds on work by Samset et al., who reported that the effects of emission mitigation will only be perceived through global temperature with a multi-decadal delay. This paper provides additional context and expresses concerns with the approach towards assessing a discernible warming response under different greenhouse gas concentration pathways. A broader debate on how to best assess and communicate emerging effects of climate mitigation in the light of natural variability seems warranted.

Publications

Reversal of the impact chain for actionable climate information

This study helps local decision-makers understand the link between the risks they want to avoid (i.e. health-related heat risks) and CO2 emissions using a new method that makes identifying critical risk levels easier for non-scientists.

Humid heat exceeds human tolerance limits and causes mass mortality

With critical physiological limits to human heat tolerance drawing ever closer, this Comment highlights the urgent need to limit further climate warming and emphasises the adaptation challenge ahead.

1.5°C-aligned 2030 and 2035 GHG emissions targets

We have produced factsheets for Australia, Brazil, China, the EU, India, Indonesia and USA showing 2030 and 2035 greenhouse gas emission reduction milestones for each jurisdiction to align with the Paris Agreement’s 1.5°C goal – both including and excluding land use, land-use change and forestry.

Spatially resolved emulated annual temperature projections for overshoot pathways

This study presents a new dataset of annual temperature projections for different overshoot pathways (when the 1.5 °C of global warming limit is exceeded). The data offers a unique opportunity to study local and regional climate change impacts of a range of overshoot scenarios, including when temperature thresholds might be exceeded, and by how much.

Geological Net Zero and the need for disaggregated accounting for carbon sinks

This study in Nature show that definitions of net zero now in widespread use will not actually stop global warming. The paper demonstrates that relying on natural carbon sinks, such as in forests or oceans, to 'offset' ongoing fossil fuel emissions will lead to continued warming.

Climate Action Tracker: 2024 warming projection update

Despite an escalating climate crisis marked by unprecedented wildfires, storms, floods, and droughts, the Climate Action Tracker annual global temperature update shows global warming projections for 2100 are flatlining, with no improvement since 2021. The aggregate effect of current policies set the world on a path toward 2.7°C of warming.

Decarbonising light-duty vehicle road transport

The Climate Action Tracker provides updated 1.5ºC compatible benchmarks for the transport sector for the world as a whole and for seven individual countries; the US, EU, China, India, Brazil, South Africa and Indonesia.

Emissions Gap Report 2024: No more hot air … please!

The 2024 edition of UNEP’s Emissions Gap Report shows how much higher nations must aim. To get on a least-cost pathway for 1.5°C, emissions must fall 42 per cent by 2030, compared to 2019 levels. G20 nations, particularly the largest-emitting members, would need to do the heavy lifting.

The role of northern forests in limiting warming to 1.5°C

Northern forests are critical in the race to net zero CO₂ by mid-century. Protecting and restoring these forests, alongside steep and rapid reductions in fossil fuel emissions, is essential both to mitigating emissions and to supporting forest ecosystem services and biodiversity.

Methodology underpinning the State of Climate Action series: 2024 update

This technical note describes the State of Climate Action series’ methodology for identifying sectors that must transform, translating these transformations into global mitigation targets primarily for 2030, 2035 and 2050 and selecting indicators with datasets to monitor annual change. It also outlines the report’s approach for assessing progress made toward near-term targets and comparing trends over time.

Rapid urbanisation and climate change key drivers of dramatic flood impacts in Nepal

New study finds the devastating floods in Nepal late September were exacerbated by rapid urbanisation and climate change. The analysis found the relentless rain, which fell on saturated ground in the late monsoon, was made at least 10% heavier and 70% more likely by climate change.

LNG shipbuilding industry heading to huge oversupply

The LNG shipbuilding industry appears to be doubling down on building new carriers, ignoring the global shift to a low carbon economy and putting itself into an even worse oversupply situation than a year ago, we find in our updated report.

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Decarbonisation targets and 1.5℃ pathways

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