Isn't it pointless trying to stop climate change - because fossil fuels are about to run out anyway?

Everyone is in a panic to try to go "green" to save the rainforests etc, and stop the ice caps melting. So they are trying to encourage us to "go green" - to stop using fossil fuels etc to cut down the amount of CO2 in the atmosphere. But surely we have already dug up and burned most of the fossil fuels in the world, so for that reason, not for reasons of climate change, we should not bother about going green, and just accept that mankind will have to choose alternative energy sources soon in any case.