Climate change is one of the biggest threats to wildlife the planet has ever faced. Around the world remperatures are changing becuase of human behaviour, leading to habitat destruction and loss and resulting in what might be the next great extinction of species (this is what happened when the dinosaurs went extinct).
One of the main reasons the climate is changing is becuase humans are using too many fossil fuels - when these are burnt they release carbon dioxide into the atmosphere, trapping heat where once it was released into space. Fossil fuels are released when burning things like petrol, diesel, coal and natural gas. Green energy such as solar panels, wind turbines and tidal energy release much less of these gases and are much better for the planet.
Other industries like farming release a lot of methane into the atmosphere which also contributes to the warming effect on the planet.
As these changes are global it can be difficult to know how to help combat these changes but everyone can do their bit! Just by walking more often, using public transport and turning off the power when you aren't using it you can make a difference.
Or why not write to your local MP or headteacher? You will be encouraging others to change and think about how their actions can aaffect wildlife and their environment.