That is a lame excuse, mostly used by people from developed countries that are responsible for the issue, so you dodge responsibility and also try to put blame on the developing country why you are continuing screwing the environment. It is like you have a history of you and your ancestors abusing your children and you don't want to stop because the new neighbor is also abusing his children too (I am thinking especially at coal plants and cars that have effects locally too, so cleaning yup your house means you will have healthier population and less CO2)