Science Assessment
and Analysis

Climate science is highly complex and the policy implications are not always clear. We make the latest climate science easily accessible for stakeholders in the international climate change arena.

 ©Sarah Depper, CC BY 2.0
©Sarah Depper, CC BY 2.0

We synthesise and advance scientific knowledge in the area of climate change science, policy and impacts to make it easily accessible for stakeholders in the international climate change arena. This includes conducting our own research (for example, to evaluate the uncertainties in climate science associated with potential mitigation pathways, project sea-level rise or evaluate impacts and risks at different levels of warming) as well as bringing together and communicating the findings of the available scientific literature and providing the context needed to understand their implications. Projections of future climate change are subject to uncertainty, as they depend on a range of developments that cannot be foreseen (e.g. emission pathways). Also, there remain important limitations in the understanding and the modeling of some key processes of the climate system. Much of our work therefore focused on understanding these key process and the probabilities associated with climate impact projections.

Latest

Researchers now know the difference half a degree can make. They can tell you why 1.5°C warming would be better than a 2°C climb in average global temperatures, because even half a degree Celsius could mean greater extremes of heat, more overwhelming rainfall and longer spells of warm weather.  
Half a degree Celsius of global warming has been enough to increase heat waves and heavy rains in many regions of the planet, researchers reported Friday. Comparing two 20-year periods—1960-79 and 1991-2010—between which average global temperatures jumped 0.5 C (0.9 F), scientists found that several kinds of extreme weather gained in duration and intensity.  

Publications

This commentary in journal Nature Climate Change discusses how evidence from the observational climate record provides useful guidance in discriminating the climate impacts of half-degree warming increments, which is high on the science agenda since the adoption of the 1.5°C temperature limit in Paris Agreement.  
The Intergovernmental Panel on Climate Change (IPCC) has accepted the invitation from the UNFCCC to provide a special report on the impacts of global warming of 1.5 °C above pre-industrial levels and on related global greenhouse-gas emission pathways. Many current experiments in, for example, the Coupled Model Inter-comparison Project (CMIP), are not specifically designed for informing this report. This article documents the design of the half a degree additional warming, projections, prognosis and impacts (HAPPI) experiment. HAPPI provides a framework for the generation of climate data describing how the climate, and in particular extreme weather, might differ from the present day in worlds that are 1.5 and 2.0 °C warmer than pre-industrial conditions.  
The Paris Agreement long-term global temperature goal refers to two global warming levels: well below 2°C and 1.5°C above preindustrial. Regional climate signals at specific global warming levels, and especially the differences between 1.5°C and 2°C, are not well constrained, however. In particular, methodological challenges related to the assessment of such differences have received limited attention. This article reviews alternative approaches for identifying regional climate signals associated with global temperature limits, and evaluates the extent to which they constitute a sound basis for impacts analysis.  
A new analysis of the scientific and policy aspects of the 1.5°C temperature limit in the Paris Agreement’s long-term temperature goal has identified a number of important areas that require more scientific research. The analysis, written by a team of scientists who have published key research papers on the science, impacts and policy aspects of the 1.5˚C limit, is a centrepiece of a collection by Nature Climate Change, Nature Geoscience and Nature on 'Targeting 1.5°C'  
This article is a first comprehensive assessment of key climate impacts for the policy relevant warming levels of 1.5 °C and 2 °C above pre-industrial levels. It finds substantial impact differences in intensity and frequency of extreme weather events, regional water availability and agricultural yields, sea-level rise and risk of coral reef loss. The increase in climate impacts is particularly pronounced in tropical and sub-tropical regions.  

Projects

IMPACT is a cross-cutting, multi-faceted project that aims to strengthen the connections between the scientific assessments of climate impacts, vulnerability and adaptation to help enable access to finance and help Small Island Developing States (SIDS) and Least Developed Countries (LDCs) implement concrete projects.  
The "Climate Action Tracker" is an independent science-based assessment, which tracks the emission commitments and actions of countries.  
Science and policy to assist and support SIDSs and LDCs to negotiate a strong international climate regime, enabling low carbon development and supporting adaptation needs.  
This project aims to establish a scientifically robust and transparent link between the latest climate-economic science data and the Climate Bonds Initiative’s project universe. The Framework's goal is to ensure that project categories certified under the Climate Bond Standards represent mitigation actions that current climate science finds most relevant in order to keep global warming below 2° C. Project period: 2015 - 2016.