Global warming is caused by greenhouse gases rising up into the atmosphere, which create a kind of blanket around the earth - trapping heat. This is a modern-day problem because the most significant greenhouse gas, carbon dioxide, is created by burning fossil fuels such as coal, gas and oil.
We have become very dependent on these fuels. For example, to provide gas for heating our homes, electricity to watch our televisions and petrol to run our cars. We do not expect people to radically change their lifestyles, but there are many ways they can use energy more efficiently without missing out on their creature comforts.
If we do not dramatically reduce our output of greenhouse gases, we won’t just have to deal with rising temperatures. We will have to cope with all the added consequences of climate change, such as a higher risk of drought and flooding.
Global temperatures have risen consistently for the past 140 years and it is now widely accepted that this change is linked to man-made greenhouse gases which have increased with industrialisation and the burning of fossil fuels. But increasing temperatures will upset the natural balance of our world and its complex weather systems - having very different effects in different places.
Some areas will be warmer, but some will be cooler, sea levels may rise, polar ice caps melt, deserts might spread across Europe and extreme weather events may become more frequent. Some areas are going to be hit far harder by climate change - even a slight change can have a dramatic effect in places which are already prone to high temperatures and severe weather.
For example, climate change may be responsible for the disastrous weather events in the Indian state of Orissa in recent years. A massive cyclone struck in 1999, killing 30,000 people and the state's worst flood for the last century occurred in 2001, leaving millions homeless and hungry as crops were ruined.
One of the injustices is that many of the countries which will be most affected by climate change - those which already endure high temperatures and extreme weather events - are those which produce relatively low amounts of carbon dioxide. Wealthy, industrialised countries tend to use far more fossil fuels than developing countries. For example, research has shown that the average person in America produces the same amount of greenhouse gases as 19 people living in India.
It might be on a smaller scale, but Leicester can also expect a "more unpredictable climate" in the future. Weather conditions will be more varied and erratic across the year. Summers will be drier and winters wetter, with fewer, but heavier bursts of rain. By 2080, the average temperature is expected to rise by about 3.20C and rainfall looks set to increase by eight per cent a year - this might not sound a lot, but as rain will fall in heavier downpours we can expect to have more flooding problems too.