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The United States is already experiencing impacts of climate change across most sectors and regions and it’s likely to get worse, according to the Fourth National Climate Assessment, published in November 2018.

The authoritative report has been written by 300 expert authors from 13 Federal institutions and other agencies, sets out a grim picture of the impacts of climate change while calling for global efforts in mitigation to reduce the many risks to the US.

This blog gives an overview of the most important recent studies on climate impacts and extreme events. Much of it will be synthesised in the IPCC special report on 1.5˚C, due out in October, which will be a key document for setting the course of climate policy at a global level.

This year’s extreme summer, still scorching central and northern Europe, is a stark illustration of the kind of climate change impacts we could see if nothing is done to reduce greenhouse gas emissions. Heat waves, droughts and other extremes will only increase in severity and frequency as the Earth continues to warm. Limiting warming to 1.5°C, as governments around the world pledged by signing the Paris Agreement, can help avoid the worst impacts of climate change.

The adoption of the Paris Agreement started a lively debate among scientists about the interpretation of several of its elements. Of particular interest has been the long-term temperature goal of limiting warming to “well below” 2°C or 1.5°C above pre-industrial levels and the question of how progress against the goal should be tracked. As there are a number of different observed datasets for global temperature – as well as methods that use climate models – it means different studies can arrive at different assessments.