1 November, 2011

Science aspects of the 2°C and 1.5°C global goals in the Cancun Agreements

Authors

Bill Hare, Michiel Schaeffer, Marcia Rocha

In the international climate negotiations, long-term global targets can serve as a guideline for policy decisions on mitigation. However, under any long-term global target, the impacts of climate change are not equally distributed over countries. The evaluation of a global target for limiting global warming needs to take into account this heterogeneity and the interests of countries that take the bigger share of impacts.

This paper reviews the scientific literature on impacts for 1.5 and 2°C warming levels with focus on risks for Least Developed Countries. We summarise observed impacts in LDCs that have been related to global mean temperature and provide an overview of projected future changes.

Publications

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1.5°C-aligned 2030 and 2035 GHG emissions targets

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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

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LNG shipbuilding industry heading to huge oversupply

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Seasonal forecast of two-metre temperature and precipitation in Tanzania: A hybrid cluster and point-by-point machine learning approach

Seasonal forecasting of atmospheric parameters is important in various fields including agriculture. This study tests how machine learning can complement dynamic models using Tanzanian seasonal forecasts and finds this process uses far less computational power.

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Decarbonisation targets and 1.5℃ pathways

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