What causes sunlight to reach the earth and prevents heat from radiating back out to space?

The Ozone layer protects the earth form the suns harmful rays but due to pollution from fossil fuels,electricity, etc the harmful rays have been allowed through which is causing our earth's temperature to rise. The harmful rays should be radiating back out to space but carbon dioxide levels have risen and although carbon dioxide has always been present the more the levels rise the more risk of human extinxtion. We should be looking after our earth but instead we're putting back the harmful fuels that took a long time to cut down but now it is taking no time at all to destroy our earth.