Global temperatures are rising due to human activity. The effects are already being felt by people around the world, from more intense heat to rising sea levels. Things are likely to get worse in the coming decades, but scientists say urgent action can still prevent the most dangerous effects of climate change. Climate is the average weather in a place over many years. Climate change is a shift in these average conditions. Climate has fluctuated naturally throughout the world's history. But scientists say there is no doubt that the particularly rapid climate changes we have seen over the past century are caused by humans. (BBC NWES)