4.As a result of the changing climate, the world'secosystems are also changing faster than everbefore. More than one-third of the world's mangroveforests? and around 20% of the world's coral reefs3have been destroyed in the last few decades. Forestsare being cut down to provide land for food becausehuman population is growing at such a rapid rate.Approximately a quarter of the land on Earth is nowused for growing food. As a result of the highertemperatures and higher levels of carbon dioxide inthe atmosphere, plants are producing more pollen,which could lead to more cases of asthma, a medicalcondition which makes it hard to breathe.