Tackling climate change is a global challenge and the Intergovernmental Panel on Climate Change (IPCC) is the organisation charged with communicating the risks, dangers and mechanisms underlying climate change to both policy makers and the general public. The IPCC has traditionally used words (e.g., ‘likely’) in place of numbers (‘70% chance’) to communicate risk and uncertainty information. Th...

Recent flooding and heavy precipitation events in the US and worldwide have caused great damage to crop production. If the frequency of these weather extremes were to increase in the near future, as recent trends for the US indicate and as projected by global climate models (e.g., US National Assessment, Overview Report, 2001, The Potential Consequences of Climate Variability and Change, Nation...

To what extent has the Intergovernmental Panel on Climate Change (IPCC) succeeded in its ambition to shape a more diverse environmental expertise? In ways are diversity important IPCC? What purposes does serve IPCC’s production of global assessments and thus knowledge general? These questions explored by analyzing quantitative demographic data latest two assessment cycles (AR5 AR6) qualitative ...

In this paper, we investigate an ensemble of atmosphere–ocean general circulation models (AOGCMs) participating in phase 3 of the Coupled Model Intercomparison Project (CMIP3), and whose dynamic behavior is emulated by the reduced-complexity climate model MAGICC6. Using a superimposed impulse in solar radiative forcing for the purposes of system identification, we identify 12 AOGCMs in the CMIP...

The climate of the New York metropolitan region is changing—annual temperatures are hotter, heavy downpours are increasingly frequent, and the sea is rising. These trends, which are also occurring in many parts of the world, are projected to continue and even worsen in the coming decades due to higher concentrations of greenhouse gases (GHGs) in the atmosphere caused by burning of fossil fuels ...

We have observed that the dry-season length (DSL) has increased over southern Amazonia since 1979, primarily owing to a delay of its ending dates (dry-season end, DSE), and is accompanied by a prolonged fire season. A poleward shift of the subtropical jet over South America and an increase of local convective inhibition energy in austral winter (June-August) seem to cause the delay of the DSE i...

Projections of future climate change made using state-of-the-art climate models suggest that changes over the coming century will be much larger than experienced over the past 100 years. The case for taking action to mitigate these human-induced (or ‘anthropogenic’) changes rests on the credibility of these models. There is a vast scientific literature on the development and testing of these mo...

On 31 March, the Intergovernmental Panel on Climate Change (IPCC) released its latest report on the impacts of climate change on humans and ecosystems (see go.nature.com/ad5v1b). These are real risks that need to be accounted for in planning for adaptation and mitigation. Pricing the risks with integrated models of physics and economics lets their costs be compared to those of limiting climate ...