Scientists and officials meeting in Japan have published the most comprehensive assessment to date of the impacts of climate change on the world.
Members of the UN's climate panel say that their report provides overwhelming evidence of the scale of these effects.
Natural systems are bearing the brunt right now but the scientists fear a growing impact on humans.
Our health, homes, food and safety are all likely to be threatened by rising temperatures, the summary says.
The report was agreed after almost a week of intense discussions here in Yokohama.
This is the second of a series from the Intergovernmental Panel on Climate Change (IPCC) due out this year that outlines the causes, effects and solutions to global warming.
This latest Summary for Policymakers document highlights the fact that the amount of scientific evidence on the impacts of warming has almost doubled since the last report in 2007.
Be it the melting of glaciers or warming of permafrost, the summary highlights the fact that on all continents and across the oceans, changes in the climate have caused impacts on natural and human systems in recent decades.
In the words of the report, 'increasing magnitudes of warming increase the likelihood of severe, pervasive and irreversible impacts'.
'Before this we thought we knew this was happening, but now we have overwhelming evidence that it is happening and it is real,' said Dr Saleemul huq, a convening lead author on one of the chapters.
The report details significant short-term impacts on natural systems in the next 20 to 30 years. It details five reasons for concern that would likely increase as a result of the warming the world is already committed to.
These include threats to unique systems such as Arctic sea ice and coral reefs, where risks are said to increase to 'very high' with a 2C rise in temperatures.
The summary document outlines impacts on the seas and on freshwater systems as well. The oceans will become more acidic, threatening coral and the many species that they harbour.
Animals, plants and other species will begin to move towards higher ground or towards the poles as the mercury rises.
Humans, though, are also increasingly affected as the century goes on.
Food security is highlighted as an area of significant concern. Crop yields for maize, rice and wheat are all hit in the period up to 2050, with around a tenth of projections showing losses over 25%.
After 2050, the risk of more severe yield impacts increases, as boom-and-bust cycles affect many regions. All the while, the demand for food from a population estimated to be around nine billion will rise.
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