Is there climate change? I don't think there are too many people that doubt this now - with the possible exception of some of the more extreme right wingers, such as Rush Limburgh and his ilk.
One of the main problems seems to be the drop in food production that is expected. A frequently used figure is a 10% drop in grain production for every 1 degree rise in temperature. Russia experienced a 40 % drop in their grain production last year during their big heatwave. The USA is experiencing a drop in grain production in spite of farmers ramping up their production efforts. Even after putting more land than ever into production yields are falling.
A bigger problem even than the higher temperatures is water. Water tables the world over, and especially in the US, are falling, due to overpumping. If farmers can't get enough water, they can't grow more food. One ton of grain requires 1,000 tons of water! Where do you get that kind of water supply? One way is to import the grain - if you import a ton of grain that is the same as getting 1,000 tons of water!
Unfortunately the US is not in the business of buying grain, we grow it, so we need the water to do that. And in doing that and exporting grain to other nations throughout the world we are destroying our own water supplies.
Our rivers are drying up, our cities are running short, and our aquifers are dropping, fast.