Climate change, land and your life

"Which is more important—food security and reducing malnutrition or halting and reversing desertification and land degradation?"

A special report, Climate Change and Land, by the Intergovernmental Panel on Climate Change (IPCC) released Aug. 7 in Geneva, will make you stop eating rice, pork, beef, hamburgers, and everything processed and genetically modified.

It says the only thing safe to eat, if you are serious about preserving the environment, for your children, grandchildren and their children, is fish.

You may have to ditch your car into the river for good. And you should also limit the amount of water you drink—a rule, which if followed seriously, will make you dead, of course. And even after you die, you will still pollute the environment.

So I advise you, if you read the report, don’t be too serious about it. Eat. Enjoy life, which is short anyway, by global standards, for Filipinos, only 68-69 years.

After all, the contribution of all Filipinos, 106 million of us, is less than one-tenth of one percent. The top six countries who contribute 60 percent of total pollution (as of 2015) are: China 28 percent; United States 15 percent; India 6 percent; Russia 5 percent, Japan 4 percent, and Germany 2 percent.

So before citizens of the Philippines suffer, shouldn’t the Chinese, Americans, Indians, Russians, Japanese, and the Germans suffer first? By so doing, the world will solve 60 percent of its total carbon dioxide emissions. And the rest of the world can live better.

According to IPCC, agriculture eats up 70 percent of total water use. Global population growth and changes in per capita consumption of food, feed, fiber, timber and energy have caused unprecedented rates of land and freshwater use.

Currently, 25-30 percent (about 1.2 billion tons) of total food produced is lost or wasted. Changes in consumption patterns have contributed to about 2 billion adults now being overweight or obese.

An estimated 821 million people are still undernourished. About 500 million people live in places turning into desert.  Soil is being lost between 10 and 100 times faster than it is forming, according to the report.

About a quarter of the Earth’s ice-free land area is subject to human-induced degradation. Soil erosion from agricultural fields is estimated to be currently 10 to 20 times (no tillage) to more than 100 times (conventional tillage) higher than the soil formation rate.

Humans degrade the land. Land use by humans is “unprecedented in human history,” the report says. Human use “affects about 60-85 percent of forests and 70-90 percent of other natural ecosystems (e.g., savannahs, natural grasslands).” And land use has caused an 11-to-14 percent drop in global biodiversity, IPCC notes.

Not only is human use of the land more pervasive than ever, it is set against a background of a warming climate. Climate change is magnifying the pressures that humans are already putting on the land.

Climate change “not only exacerbates many of the well acknowledged ongoing land degradation processes” of managed landscapes, such as croplands and pasture, but it “becomes a dominant pressure that introduces novel degradation pathways in natural and semi-natural ecosystems,” the report says.

The report also notes that “changes in extreme weather and climate have negative impacts on food security through regional reductions of crop yields.” Around 10 percent of cereal production has been lost globally because of extreme weather events.

Since 1961 methane emissions from ruminant livestock, which includes cows as well as sheep, buffalo and goats, have significantly increased, notes the New York Times quoting IPCC. Yearly, forested land that is cleared—much of that propelled by demand for pasture land for cattle—releases the emissions equivalent of driving 600 million cars. 

Cattle are significant producers of methane, another powerful greenhouse gas, and an increase in global demand for beef and other meats has fueled their numbers and increased deforestation in critical forest systems like the Amazon. 

Land contributes an annual value of $75 trillion to 85 trillion—to the global economy, an amount greater than the world’s GDP.

Per IPCC data, humans have appropriated three-quarters of the ice-free land globally. About 12-14 percent of that area is used for growing crops, 22 percent are managed or planted forests; and 37 percent is grassland for grazing and other uses.

Warming—and changes in rainfall patterns—have “altered the start and end of growing seasons, contributed to regional crop yield reductions, reduced freshwater availability, and put biodiversity under further stress and increased tree mortality.”

“Conversion of natural land, and land management, are significant net contributors to GHG [greenhouse gas] emissions and climate change, but land ecosystems are also a GHG sink.”

So which is more important—food security and reducing malnutrition or halting and reversing desertification and land degradation?

The world’s forest declined by 3 percent from 1990-2015. Satellite data suggest that forest loss is accelerating.

Warming conditions and changing rainfall patterns will also “trigger changes in land—and crop management, such as changes in planting and harvest dates, type of crops, and type of cultivars”, the report notes, “which may alter the conditions for soil erosion.”

The air can generally hold around 7 percent more moisture for every 1 degree Celsius of temperature rise. This means a warmer climate has the potential for more intense rainfall events, which “increase the erosive power of rainfall (erosivity) and hence increase the likelihood of water erosion,” the report says.

Heavy rainfall and flooding can also “delay planting, increase soil compaction, and cause crop losses,” the report says, and “flooding associated with tropical cyclones can lead to crop failure from both rainfall and storm surges.” In some cases, this flooding can affect yields more than drought, the report notes—particularly in tropical regions, such as India, and in some mid- and high-latitude regions, such as China and central and northern Europe.

Extreme heat events can reduce photosynthesis in trees, restrict growth rates of leaves and reduce growth of the whole tree, the report notes. Forests can become less resilient to future heat stress as extreme events occur more often, the report adds, and “widespread regional tree mortality may be triggered directly by drought and heat stress (including warm winters) and exacerbated by insect outbreak and fire.”

biznewsasia@gmail.com