Climate Change – Deforestation

Deforestation is directly related to climate change. The main reasons for the warming are the burning of fossil fuels (oil, coal, and natural gas) and deforestation, which are adding more greenhouse gases to the atmosphere.  Carbon dioxide emissions from deforestation add 10 percent or so to global warming by reducing the quantity of CO2 that the world’s forests pull from the atmosphere

Deforestation is connected to food supplies and wasted food supplies also contributes to greenhouse gases. World Wildlife did a study of food sources in 2018:

“In the near-term, food production is sufficient to provide for all, but it doesn’t reach everyone who needs it. In fact, one-third of the world’s food—1.3 billion tons—is lost or wasted at a cost of $750 billion annually. When we throw away food, we waste the wealth of resources and labor that was used to get it to our plates. In effect, lost and wasted food is behind more than a quarter of all deforestation and nearly a quarter of global water consumption. It generates as much as 10% of all greenhouse-gas emissions. 

“Another negative aspect of food waste is its connection to species loss. Consider this: Food production is the primary threat to biodiversity worldwide, expected to drive an astonishing 70% of projected terrestrial biodiversity loss by 2050. That loss is happening in the Amazon, where rain forests are still being cleared to create new pasture for cattle grazing, as well as in sub-Saharan Africa, where agriculture is expanding rapidly. But it’s also happening close to home. 

 “These wasted calories are enough to feed three billion people—10 times the population of the United States, more than twice that of China, and more than three times the total number of malnourished globally. Wasted food may represent as much as 10% of global greenhouse gas emissions, and is a main contributor to deforestation and the depletion of global water sources. 

Deforestation is also related to water supply

Every tree in the forest is a fountain, sucking water out of the ground through its roots and releasing water vapor into the atmosphere through pores in its foliage. In their billions, they create giant rivers of water in the air – rivers that form clouds and create rainfall hundreds or even thousands of miles away.

A growing body of research suggests that this hitherto neglected impact of deforestation could in many continental interiors dwarf the impacts of global climate change. It could dry up the Nile, hobble the Asian monsoon, and desiccate fields from Argentina to the Midwestern United States.

We are used to thinking of rainfall as the end result of water evaporating from the oceans. In coastal regions that is overwhelmingly the case. But it turns out that the interiors of continents often get most of their precipitation from water that has been rained out and recycled back into the air several times in a precipitation cascade following the winds. The further inland, the more dominant this recycling becomes

Some of the recycling is straightforward evaporation from lakes, rivers, or wet soil. But much of it is fast-tracked by plants, and especially trees. Tree roots tap moisture from deep in the soil. This circulation system is driven by releases of moisture into the air through their leaves via transpiration.

U.S. think tank Forest Climate Analytics and Nancy Harris of the World Resources Institute published a study that concluded that “tropical forest loss is having a larger impact on the climate than has been commonly understood.”They warned that large-scale deforestation in any of the three major tropical forest zones of the world – Africa’s Congo basin, southeast Asia, and especially the Amazon – could disrupt the water cycle sufficiently to “pose a substantial risk to agriculture in key breadbaskets halfway round the world in parts of the U.S., India, and China.”

In  a study of tropical areas downwind of deforestation, Dominick Spracklen of Leeds University in England found that “air that has passed over extensive vegetation in the preceding few days produces at least twice as much rain as air that has passed over little vegetation.” He predicts that forest loss is set to reduce dry-season rainfall across the Amazon basin by 21 percent by 2050. 

Meanwhile, lost forests are usually replaced by agriculture, which produces its own emissions. Add in these impacts and the real contribution of deforestation to global climate warming since 1850 is as much as 40 percent. At that rate, tropical deforestation could add 1.5 degrees Celsius (2.7°Fahrenheit) to global temperatures by 2100 – even if we shut down fossil fuel emissions tomorrow, calculates Natalie Mahowald of Cornell University.

But there are local effects, too. Forests moderate local climate by keeping their local environments cool. They do this partly by shading the land, but also by releasing moisture from their leaves. This process, called transpiration, requires energy, which is extracted from the surrounding air, thus cooling it. A single tree can transpire hundreds of liters of water in a day. Each hundred liters has a cooling effect equivalent to two domestic air conditioners.

The case of Brazil

The fires are related to the desire to clear more land for cattle operations. Brazil is the world’s largest exporter of beef, providing close to 20% of the total global exports. The growth of Brazil’s beef industry has been driven in part by strong demand from Asia — mostly China and Hong Kong. These two markets alone accounted for nearly 44% of all beef exports from Brazil in 2018

And a trade deal struck in June between South America’s Mercosur bloc of countries and the European Union could open up even more markets for Brazil’s beef-packing industry.

Brazil’s space research center (INPE) said this week that the number of fires in Brazil is 80% higher than last year. More than half are in the Amazon region, spelling disaster for the local environment and ecology

Environmental campaigners blame this uptick on Brazil’s president Bolsonaro, who they say has encouraged ranchers, farmers, and loggers to exploit and burn the rainforest like never before with a sense of impunity.

The Amazon rainforest, known as “the planet’s lungs”, is known for producing about 20% of the world’s oxygen, the answer may be simple. Eat less meat.

Beef is responsible for 41% of livestock greenhouse gas emissions, and that livestock accounts for 14.5% of total global emissions. And methane — the greenhouse gas cattle produce from both ends — is 25 times more potent that carbon dioxide.