Climate change is a global problem. The world is already around a degree warmer than it was, due to extra greenhouse gases in the atmosphere from human activity. Scientists have warned for some time that a temperature rise of two degrees or more risks severe and potentially irreversible changes to our planet. 2016 is set to be the warmest year ever recorded. If so, it will be the third record warmest year in a row. Last year's historic Paris Agreement was an important step towards tackling this. But the effects of climate change are already being felt in the UK. Average temperatures are increasing and there is a trend towards milder winters and hotter summers. We can also expect more frequent floods like those who have seen in recent years and there are plenty of other challenges on the horizon. Which is why the Committee on Climate Change has carried out a comprehensive scientific assessment of the risks and opportunities for the UK. The climate change risk assessment is the result of more than three years of work involving hundreds of leading scientists and experts from both the public and private sectors. It shows that the greatest threat to the UK come from periods of too much or too little water, increasing average and extreme seasonal temperatures and rising sea levels. Action is needed to tackle six key risks. The increasing chance of more severe and widespread flooding, risks to public health from higher temperatures, including in overheating homes. A risk of shortages in public water supplies and scarce water for farming. A threat to nature, including loss of native species. Food price spikes and potential disruption to UK and global food production. And risks from new and emerging pest and diseases affecting people, animals and plants. The longer action is delayed to reduce greenhouse gas emissions and adapt to the changes, the higher the costs and risks will be. Climate change is happening now. This new UK risk assessment identifies where more effort is necessary and urgent to address these risks. It's time to act.