10 October, 2017

Getting it right matters – temperature goal interpretations in geoscience research

Authors

Joeri Rogelj, Carl-Friedrich Schleussner, William Hare

The adoption of the 1.5°C long-term warming limit in the Paris Agreement made 1.5°C a ‘hot topic’ in the scientific community, with researchers eager to address this issue. Long-term warming limits have a decades-long history in international policy. To effectively inform the climate policy debate, geoscience research hence needs a core understanding of their legal and policy context.

This article describes this context in detail, and illustrates its importance by showing the impact it can have on global carbon budget estimates.

The 1.5℃ limit

Publications

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.

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.

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.

Fracking the Kimberley: the Canning Basin development plans

We've calculated the climate implications of fracking the Canning basin, part of the remote and pristine Kimberley region in Western Australia. Four companies have their eyes on this region, home to the endangered bilby.

Australia's global fossil fuel carbon footprint

This report unpacks the global carbon footprint from Australia's exported fossil fuels, especially coal and gas; exports that are set to continue at the same level through to 2035, threatening the 1.5˚C warming limit.
Australia has a global carbon footprint that far exceeds its economic size and population - and is responsible for around 4.5% of global fossil carbon dioxide emissions, with 80% of those emissions coming from its fossil fuel exports.

Evaluating the near and long-term role of carbon dioxide removal in meeting global climate objectives

For 1.5°C pathways with limited overshoot, most of the mitigation between now and 2030 should come from emissions reductions (70%), with reductions from cutting non-CO2 emissions (20%) and land-based carbon dioxide removals such as afforestation and preventing deforestation (10%) making up the remainder.

The 1.5°C limit and risks of overshoot

This briefing looks at what the 1.5°C limit means in terms of adaptation and loss and damage for the most vulnerable countries and regions. It finds that slowing down warming is critical to buy us time to adapt and also to avoid irreversible loss and damage. Even if warming rises above 1.5°C (overshoot) we can bring it down again with ambitious emissions reductions.

Le seuil de +1,5°C et le risque de dépassement de ce seuil

Ce rapport examine ce que la limite de 1,5 °C signifie en termes d'adaptation et de pertes et dommages pour les pays et régions les plus vulnérables. Il constate qu'il est essentiel de ralentir le réchauffement pour nous donner le temps de nous adapter et pour éviter des pertes et des dommages irréversibles. Même si le réchauffement dépasse 1,5 °C, nous pouvons le faire baisser à nouveau en réduisant les émissions de manière ambitieuse.

Kipppunkte und kaskadische Kippdynamiken im Klimasystem

Dieser im Auftrag des deutschen Umweltbundesamtes erstellte Bericht befasst sich mit Kippelementen - sensible Komponenten des Erdsystems, die bei Überschreiten kritischer Schwellenwerte (Kipppunkte) irreversiblen Veränderungen ausgesetzt werden können. Er unterstreicht, dass selbstverstärkende Mechanismen zwischen diesen Elementen zu schnellen, irreversiblen Veränderungen führen können.

Limited reversal of regional climate signals in overshoot scenarios

This peer-reviewed paper analyses what happens in an 'overshoot scenario' - where temperature rise peaks just above 1.5°C, but then return below it by the end of the century. It concludes that despite a drop in warming, regional climate changes may only be partially reversed in the decades after peak warming, demonstrating the value of limiting peak temperatures to as low as possible.

Adjusting 1.5°C climate change mitigation pathways in light of adverse new information

This study uses an integrated assessment model to explore how 1.5°C pathways could adjust in light of new adverse information, such as a reduced 1.5°C carbon budget, or slower-than-expected low-carbon technology deployment.

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Decarbonisation targets and 1.5℃ pathways

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