'Urgent need' of climate change fix, says top UK expert
A top government scientist has warned that climate change will mean many more floods, droughts and storms over the next 25 years.
Sir John Beddington says there's a "need for urgency" to fix the problem.
He says people may be slow to take action because the Earth's climate system reacts slowly to changes.
This means there are long delays between rises in carbon dioxide levels in the atmosphere and the changes in weather patterns.
Sir John says there's enough carbon dioxide in the atmosphere now, to cause plenty of bizarre weather over the next few decades.
When fossil fuels like oil, gas and coal are burnt they release the gas carbon dioxide - also known as C02 - which most scientists say warms up the Earth's atmosphere, causes changes in the weather.
Not everyone agrees though. Some experts challenge these claims, saying there's not enough evidence to prove that climate change and global warming are happening.