What is the optimum temperature?

Australian grape-grower Erl Happ became interested in climate when trying to work out what climate was best for grape-growing. And, as every grape grower knows, some climates are better for grapes than others. So instead of the common academic focus on average temperature, Happ became interested in how that average is made up. He looked at temperature by region and season rather than by some uninformative global average. What he found was that temperatures in different regions and seasons moved in different directions at the same time. While one region or season was cooling another was warming.

So this regional/seasonal disparity very strongly made an explanation in terms of CO2 useless. AGW theory could explain uniform warming only and uniform warming is NOT happening. Looking at average temperature artificially hides what is actually happening.

He sees a large influence for clouds in temperature change, and like many skeptics sees the influence as being "more-clouds=cooling". Warmists say the opposite of course. I don't find the argument he uses to justify that claim particularly strong but there are other arguments leading to the same conclusion so that is not really a problem.

What IS important I think, is his emphasis on what the optimum temperature is at any point on the earth's surface. And he defines optimum as what is best for plant growth -- seeing that we all ultimately depend on plants for food and much else.

He says that 25 degrees Celsius is optimum and, since I come from a place (tropical Australia) where the temperature is around that, I have to agree. Anybody who has seen the mad growth of vegetation in the tropics can be in no doubt that most of the earth is TOO COLD. So even if the Warmists were right, we have nothing to fear.

And even Warmists these days are retreating from the rising sea level scare. 91% of the earth's glacial ice is in Antarctica and Antarctica is way too cold for any foreseeable temperature rise to melt the ice there.

I reproduce what Happ says about optimum temperature:

What is the utility of the globe to humanity at this particular point in the evolution of the Earth's disparate climatic regimes? Has there been an improvement or deterioration in recent times? To answer these questions we must look at the pattern of temperature change by latitude.

Summer maxima are short of the 25°C optimum temperature for plant growth.

Why is it considered that the globe is in danger of becoming too warm? Our interest is in ensuring that the capacity of the planet to support life in all its forms is not impaired. In the warmest parts of the globe, the parts considered thus far, temperature is sub optimal for plant growth and particularly so in the southern hemisphere. All life depends upon plants. We would be better off if the planet were warmer. It is further cooling that represents a threat to human welfare. We have plenty of scope on the upside.

Another recent article here on the theme that more warming would be good for us.

Posted by John J. Ray (M.A.; Ph.D.).