No, its not Malthusian... It is common sense
First, to compare what -I am saying with Malthus suggests you dont understand the argument he, or I, are making.
We already see hardships from regional climate variations (natural or man-made) that affect large populations greatly. To argue that a global climate shift won't be that big a deal is to ignore all reason. To argue that it will be just peachy keen so we dont need to even worry about it is optimism bordering on insanity. We need to seriously start looking at these changes and either ways to prevent them, or ways to adapt to them, that is the ONLY logical course!