Justin Gillis answer to Question 14. How does agriculture affect climate change?
It’s a big contributor, but there are signs of progress.
The environmental pressures from global agriculture are indeed enormous.
The demand for food is rising, in large part because of population growth and rising incomes that give millions of once-low income people the means to eat richer diets. Global demand for beef and for animal feed, for instance, has led farmers to cut down huge chunks of the Amazon rain forest.
Efforts are being made to tackle the problems. The biggest success has arguably been in Brazil, which adopted tough oversight and managed to cut deforestation in the Amazon by 80 percent in a decade. But the gains there are fragile, and severe problems continue in other parts of the world, such as aggressive forest clearing in Indonesia.
Scores of companies and organizations, including major manufacturers of consumer products, signed a declaration in New York in 2014 pledging to cut deforestation in half by 2020, and to cut it out completely by 2030. The companies that signed the pact are now struggling to figure out how to deliver on that promise.
Many forest experts at the Paris climate talks in late 2015 considered the pledge as ambitious, but possible. And they said it was crucial that consumers keep up the pressure on companies from whom they buy products, from soap to ice cream.
My answer to Question 14. How does agriculture affect climate change?
Whenever a forest is cut down and the earth gets tilled the local microclimate changes, and not for the better. The earth warms about 0.8 degrees C, the evapotranspiration is drastically reduced, the ground dries up having lost its protective shade. That is why it is an insane idea to cut down the rainforests of Borneo to produce biofuel.
Thanks to increasing CO2 levels agriculture is in much better shape than before.
CO2, the life-giving gas, not “Carbon Pollution”. A Limerick – and explanation.
What then is this “Carbon Pollution”?
A sinister, evil collusion?
CO2, it is clean,
Makes for growth, makes it green,
A transfer of wealth, a solution.
CO2 concentration has increased from about 280 ppm in pre-industrial times to 405 ppm today, and is increasing at a rate of 2 ppm per year. We are way past the point of no return, 350 ppm which would lead to a temperature catastrophe. (1) But instead, something rather interesting is occurring. The earth is getting greener! (2) This 40 % increase in CO2 the last 250 years has led to a more than 30 % increase in agricultural production all by itself without adding fertilizer or using higher yielding seeds. (3) Thanks to this we can now feed an additional two billion people on earth without starvation. The news are so good, that the per capita food production is increasing, even as the population is increasing. (4)
Look at it this way. The value of basic agricultural products is more than 1.5 trillion dollars worldwide. 30% of that is due to increased CO2. That means that the CO2 emitted is worth 450 billion dollars, spread out over all farmers and ranchers worldwide. This wealth transfer is occurring right now, and knows no national boundary. It is a gift from the developed countries to the rest of the world. Who could be against that?
It turns out that this wealth transfer occurs without global governance. The leaders of the world will not have their say in who gets the wealth transfer, the U.N. bureaucrats will not get their cut, and politicians cannot get a campaign issue since it occurs without their involvement.
So to recapture the initiative they renamed this life-giving gas “Carbon pollution” and managed somehow to get the Supreme Court to agree with the notion that CO2 is a pollutant.
How can that be? They argued that CO2 is a greenhouse gas, which is true. It is second only to water vapor. It is responsible for about 9 degree Celsius rise in global temperature, and if CO2 increases, so does the greenhouse effect and the temperature increases. This in turn leads to more water vapor in the air, and water vapor is the strongest greenhouse gas, so there is a risk of reaching a “tipping point” when we could experience a thermal runaway of the planet. All of this is true, so U.N. and many governments around the world have sponsored studies to model climate change, over a hundred models have been constructed, and they all come up with rather gloomy forecasts. The research is so intense that over 3 billion dollars of government monies are spent yearly on climate change research.
All models show a similar pattern, a fairly steep and more or less linear rise in temperature as CO2 increases. There is only one major thing wrong with them. They do not agree with what is happening to the global temperature. We have now had 224 months (Sep 2015) without any global warming, in fact, the trend is down. (5)
What is wrong with the models? They all assume a passive earth, where there is no negative feedback to the changing environment. It turns out, the earth has a “governor”, and it can be expressed in one word, albedo, which means “whiteness” or how much of the incoming sunlight that gets reflected back into space.
The major albedo changers are the amount of ice around the poles and clouds, but even land use changes such as forests cut down and replaced by agriculture and urbanization.
When there is snow or ice on the ground, more sunlight gets reflected and it gets colder still. Urban heat islands are warmer than the surroundings, airports are warmer than its surroundings. Interestingly, that is where we are placing our new weather stations. (This is great for pilots that have to evaluate take-off and landing conditions, but is less than ideal for climate research. But then again, climate research has moved from the realm of physical science to political science, where different rules do apply.)
The most important albedo changers of the earth are clouds. Without them no land based life would be possible since clouds serve both as rainmakers and temperature stabilizers. If there were no clouds the equilibrium temperature at the equator would be around 140 degrees F.
Over the oceans, in the so called “doldrums” where there are no trade winds, the mornings start with a warm-up, and when the conditions are right a shower or thunderstorm occurs. The ambient temperature is usually between 84 and 88 degrees when this happens. As CO2 concentrations increase thunderstorms occur a few minutes earlier and last a little bit longer, but they are no more severe and as a result the average temperature stays the same. (5)
In desert areas of the world this temperature regulator doesn’t work well, so deserts will receive the full force of temperature increase which is 1.6 degrees Fahrenheit per doubling of CO2 levels.
In the temperate region the temperature increase will be somewhere in between. Dry days will be warmer, cloudy and rainy days will have the same temperature as before, since the regulator starts to function.
The polar region is a special case. None of the models have done a good job at modeling the clouds at the poles, especially the South Pole. (6) They will warm up more than 2 degrees F, how much is a question. In the South average temperatures will rise from – 70 degrees F in the interior all the way to maybe – 63 degrees F, and come closer to freezing in the summer at the northern edges. There may be added snowfall that will expand the ice sheet. The Antarctic ice sheet has set new records since record keeping began, and is at the moment bottoming out at 30% more ice than the 30 year average. (7)
The North Pole region is even more complicated since it is partially land, partially ocean. The oceanic ice cap has been shrinking at a fairly constant rate the last 30 years, but last year it broke the trend and grew back to break the trend line. The winter snow cap has remained at about the same level year to year with a slightly positive trend line, this year being no exception. So, why is the snow cover growing slightly, but ice cover shrinking? The common explanation has been global warming, but the ice cover kept shrinking even as the temperature increase leveled off. There are two possible explanations: Warming oceans and changes in pollution. The North Atlantic Oscillation has been mostly positive (warmer) since 1970 and has only recently turned negative, so that is certainly part of the cause of the shrinking of the icecap, but another candidate is even more likely: Carbon Pollution. With that I do not mean CO2, but good old soot, spewing out from the smokestacks of power plants in China. 45% of all coal burned is burned in China, often low grade lignite with no scrubbers. The air in Beijing is toxic to humans more days than not. Some of that soot finds its way to the arctic and settles on the ice, changing its albedo, and the sun has a chance to melt the ice more efficiently. This occurs mostly in the months of August and September when the Sun is at a low angle anyway, so the changing of the albedo has very little effect on temperature. The net result of all this is that the temperature in the North Pole region will rise about 3 degrees Fahrenheit for a doubling of the CO2. This will have a very minor effect on the Greenland ice cap since they are nearly always way below freezing anyway (-28 degree C average). The largest effect will happen in August and September in the years when all new snow has melted and the soot from years past is exposed. This happened two years ago with a sudden drop in albedo for the Greenland ice. It will also lead to an increase in the precipitation in the form of snow, so the net result is the glaciers may start growing again if the amount of soot can be reduced.
The conclusion is: The temperature regulator of the earth is working quite well, and the increase in temperature at the poles is welcome as it lessens the temperature gradient between the tropics and the polar regions, which in turn reduces the severity of storms, since they are mostly generated by temperature differences and the different density of warm, humid and dry, cold air. (8) The Polar Bears will do quite well, their numbers have more than doubled in the last 50 years.
(1). This is a message from 1010global.org. Their aim was to reduce carbon emissions by 10% in 2010.
(2). The earth is getting greener! https://lenbilen.com/2013/03/19/co2-the-solution-to-climate-change/
(5). Reality versus climate models.(6) Projected cloud cover for various climate models versus reality.
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