The latest assessment of the climate system paints a clear picture of how human activity has led to unprecedented changes in the climate system.   A report on the science of climate change by the Intergovernmental panel for climate change (IPCC) in 2021 she described in detail the "unequivocal" role of humans and concluded that halting further warming would require "substantial and sustained" reductions in greenhouse gas emissions. While the IPCC reports provide politicians and governments with vital and authoritative evidence on climate change, the enormous time and effort that goes into them means that they are only updated every 5 to 10 years. (Dr Debbie Rosen, Prof Piers Forster)