No one is immune to the impact of climate change, which is fuelling war, hastening natural disasters, causing the extinction of species and threatens to drag societies back into poverty, the most comprehensive study into the phenomenon has warned.
"Nobody on this planet is going to be untouched by the impacts of climate change,'' IPCC chairman Rajendra Pachauri told a press conference at the launch of the report from the Intergovernmental Panel on Climate Change, in Yokohama, Japan.
Michel Jarraud, secretary-general of the World Meteorological Organisation, said the report, the most comprehensive to date, said it showed that "now, ignorance is no longer a good excuse" for inaction to tackle the threat.
A Turkana woman scoops water from a dry river bed in Lodwar
The wide-ranging report says climate change is now affecting
- Affecting global poverty
- Changing coastlines
- Destroying, and rarely benefiting, food systems
- Causing animal extinctions
- Fuelling riots over food prices
- Damaging worldwide security
- Destroying homes, even in England and Wales
- Causing wildfires, floods, hurricanes, tornados and droughts
In seven years after the first report from the UN, climate change is no longer a looming threat to future generations, the panel of experts said. It is a reality for human beings in 2014.
"All aspects of food security are potentially affected by climate change," the report said.
Crop yields are slowing because of temperature changes and patterns of rainfall. Fish supplies have fallen by around 50%, coral reefs are being damaged and wildfires are becoming more frequent.
Animals are threatened, with the report saying “A large fraction of both terrestrial and freshwater species face increased extinction risk under projected climate change during and beyond the 21st century, especially as climate change interacts with other stressors such as habitat modification, over-exploitation, pollution and invasive species."
In 2008, worldwide riots, including the incident in Tunisia said to have sparked the Arab Spring, were originally based on soaring food prices.
The report also connected climate change to rising food prices and political instability, for instance the riots in Asia and Africa after food price shocks in 2008.
"Climate change can indirectly increase risks of violent conflicts," the report said, and warned more could be to come, adding that hundreds of millions of people could be dispersed by flooding along south Asia's coastline by 2100.
And experts warned that in many cases, people are ill prepared to cope with the risks of a changing climate.
Recent extremes such as heat waves, droughts, floods and wildfires show how vulnerable humans are to variations in climate, it said.
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And there has been a decrease in the number of people dying from the cold but an increase in heat-related deaths in some areas, such as England and Wales, the report suggested. Up to 2050, climate change will mostly exacerbate existing health problems, and across the 21st century will lead to increases in ill-health, particularly in poorer countries.
Friends of the Earth's executive director, Andy Atkins, said: "We can't continue to ignore the stark warnings of the catastrophic consequences of climate change on the lives and livelihoods of people across the planet.
"Giant strides are urgently needed to tackle the challenges we face, but all we get is tiny steps, excuses and delays from most of the politicians that are supposed to represent our interests.
"Governments across the world must stand up to the oil, gas and coal industries, and take their foot of the fossil fuel accelerator that's speeding us towards a climate disaster."
Vicente Barros, co-chair of the IPCC study on climate change impacts, vulnerabilities and adaptation, from the University of Buenos Aires, Argentina said: "We live in an era of man-made climate change.
"In many cases, we are not prepared for the climate-related risks that we already face. Investments in better preparation can pay dividends both for the present and for the future."
In Europe, there will be increased economic losses and more people affected by flooding in river basins and coasts, in the face of rising sea levels and heavy rainstorms.
The UK will need to spend on better flood defences, as climate change fuels extreme weather
Most of the flood damage can be avoided by measures such as flood defences, but the costs of increasing protection will be high.
There will also be a reduction in water availability from rivers and groundwater, while increased heatwaves will damage human health and well-being, crop production and increase air pollution and the risk of wildfires in southern Europe and parts of Russia.
The UK's Energy Secretary Ed Davey welcomed the publication of the report and said the onus was on the world to act.
“The science has spoken," he said. "Left unchecked, climate change will have far reaching consequences for our society.
“The UK is leading from the front and working with our European partners. We’ve adopted some of the most ambitious climate change targets and are investing in low carbon and energy efficiency technologies.
“This evidence builds the case for early action in the UK and around the world to lessen the risks posed by climate change. We cannot afford to wait.”
Professor Corinne Le Quere, director of the Tyndall Centre for Climate Change Research at University of East Anglia said: "The human influence on climate change is clear.
"The atmosphere and oceans are warming, the snow cover is shrinking, the Arctic sea ice is melting, sea levels are rising, the oceans are acidifying, some extreme weather events are on the rise, ecosystems and natural habitats will be upset.
"Climate change threatens food security and world economies.
"We need rapid and substantial cuts in carbon emissions and a move away from burning fossil fuels if we are to limit global climate change below two degrees and mitigate these impacts."
Professor Sam Fankhauser, of the London School of Economics and a contributing author to the report said: "In the UK and the rest of northern Europe, we will need to cope with increasing risks from coastal and inland flooding, heat waves and droughts.
"The UK and all rich countries must also provide significant support to help poor countries, which are particularly vulnerable, to cope with the impacts of climate change."
The report from the IPCC forms the second part of a wide-ranging review of the evidence surrounding climate change. The first part of the "fifth assessment report" which looked at the science of climate change, concluding there was a 95% chance that humans were responsible for the majority of global warming, was published last year.
The second part of the study drew on contributions from hundreds of experts from 70 countries, and more than 1,700 expert and government reviewers.