Sit up class!
Straight backs. Face the front.
Davidson stop reading comics under the desk. Will the big lout at the back put the stock market report away. Do your trading at playtime.
Take out your copy of Climate Change: The Facts 2017.
No not the 2014 one Lizzie. Stop making faces at her Gab. It’s not her fault that she’s slow.
Turn to page 189. Chapter 14. Carbon Dioxide and Plant Growth by Dr Craig D Idso, the founder, former president and current chairman of the board of the Centre for the Study of Carbon Dioxide and Global Change.
This is an amazing paper and it falls right into my original ballpark – Agronomy, the integrating part of Agricultural Science that I studied in Hobart and then at the Waite Ag Research Institute in Adelaide. The Institute is a centre of excellence located next to the CSIRO Soils Division and the Wine Research Institute. Wine was not the big deal that it is these days, we were still taking it from glass flagons and beer was still overwhelmingly the drink of preference.
No I am not going to tell you about my research again, I told you about that when we did the neutralisation of the oceans and the barrier reef.
You all know that the level of CO2 is seriously sub-optimal for plant growth and a revelation in this paper is that the temperature is arguably sub-optimal as well.
The trend in CO2, from a preindustrial baseline a bit under 300 ppm we are now about 400 and we could reach 800 by the end of the century under the “business as usual” scenario.
Productivity. He cites figures for the extra growth of plants with 300ppm extra CO2 (not sure about the baseline). Average for herbaceous plants is 33% extra biomass. Especially strong performers are fruit of all kinds including grapes and also carrots and turnips near 70% extra.
Trees do even better, woody plants average 50% more biomass with the extra CO2.
Many aquatic plants do better as well, although there has been less study of them.
Yes Johanna I know he’s still reading comics. You don’t need to be a tittle tattle.
Enhanced water efficiency
This is a doozey because water is a limiting factor many places especially for broad acre farming and grazing where irritation is not an option.
You don’t need to laugh Bruce, you know I meant irrigation.
Higher CO2 reduces the opening of the stomata (pores) in the leaves which give out water vapour (the main loss of water from the plant). They also produce less stomata. One might expect this to reduce the intake of CO2 but apparently with higher concentrations that is not an issue.
Enhanced water efficiency enables plants to expand into drier areas. This is already being observed to reduce soil erosion as a collateral benefit.
More organic matter. More growth means more food and fibre. It also means more organic matter returning to the soil to build up soil structure and fertility and the population of earthworms, another collateral benefit with positive feedback effects.
Amelioration of environmental stresses
Tomorrow the class will cover the additional benefits of CO2 including the major biosphere impacts and the possibility that CO2 enhanced crops will do so much better with slightly higher temperatures that the nett benefits of warming will exceed the most optimistic calculations based on the impact of CO2 alone.
That’s it class, it is playtime and I’m dying for a fag, I mean a smoke. See you tomorrow and Lizzie, do bring Climate Change: The Facts 2017.