Dr Grumble's GP tells him that she is being advised by the Department of Health to plant trees. Trees are apparently going to prevent her patients from suffering from the effects of global warming. They are so important that the Department of Health even advises planting trees on the top of multi-storey car parks. You wouldn't think there would be enough soil for trees on the top of a multi-storey. Perhaps they will be in pots. In which case somebody is going to have to water them.
Dr Grumble found all this hard to believe but he has found a few pictures of trees on the tops of car parks and he has also found the original Department of Health document (pdf) recommending this.
This solution to global warming is slightly reminiscent of the Protect and Survive advice Dr Grumble's generation used to be given on how to survive a nuclear war. This booklet was so daft Dr Grumble thought it must have dated back to the 50s or 60s. Amazingly, a quick check on Wilipedia shows that it was published in 1980.