Before we get into detail about plant biology and ecology, let us see what is being said about the effect of CO2 emissions on climate. Specifically, it is said that the earth warmed during the twentieth century. In truth, taking the earth as a whole, including parts of the earth where no-one lives and where crops are not grown (i.e most of the earth), a very small amount of warming occurred, about half a degree overall, none of which can be attributed to CO2 emissions in any robust scientific way – it has all the hallmarks of natural variation. Some parts of the earth cooled and some warmed.
We are told that the effects of future warming, coupled with decreasing rainfall, will cause terrible difficulties for crop production in the tropics and equatorial areas, because many crops in those regions are already on the limits for heat damage, and are already badly stressed due to drought (we will see the evidence in later posts that the best solution for crops that are heat or drought stressed is increased atmospheric CO2). We are told that the likely future scenarios will be worst for countries in the tropics and equatorial zones. Seldom are we told that the same scenarios predict much-needed warmth to northern Canada, northern Europe and Siberia, bringing vast tracts of land into agricultural use, which with the increased atmospheric CO2 will enable greatly increased food production – and that in countries that have the infrastructure, the technology, and the capital to make the best use of it.
But is it true that trends are pointing towards impending catastrophe in sub-Saharan Africa and South Africa? Not at all, if trends from the nineteenth century are anything to go by.