Expedition 28 Crew / International Space Station / NASA
Over the next few days, the Biden administration is expected to announce plans across the economy to drastically reduce greenhouse gas emissions in America by 2030.
The Biden administration aims to speed up the process to avoid a turning point in the climate, which scientists warn is fast approaching. If global warming continues at its current rate, rising seas and torrential rains will flood cities around the world, forest fires and hurricanes will become even more destructive, and many more plant and animal species will disappear.
But reducing emissions, even sharply, will not immediately solve the problems in the Earth’s atmosphere. It took decades for greenhouse gases to accumulate in the atmosphere and capture heat, and it will take centuries for these gases to dissipate once people decide to stop pumping them into the air.
“When you emit carbon dioxide, the climate changes for a long time,” said Solomon Hsiang, a climate scientist and co-director of the climate impact lab at the University of California, Berkeley. “And so we somehow have to deal with this baggage, no matter what.”
All living things will still have to adapt to the warming climate. Today’s adults will cope with extreme weather conditions in the coming decades. But if countries transform their economies to drastically reduce heat capture emissions, today’s kindergartens can inherit a safer world when they reach middle age.
“It’s like riding a giant train, which is very heavy. You press the brakes. The train lasts for a while,” explains Hsian. “There is a certain amount of heating that we would continue to experience,” even with dramatic reductions in greenhouse gas emissions. It will take decades for forests, oceans and other natural systems to absorb all the excess greenhouse gases accumulated in the atmosphere.
Why greenhouse gases continue
The main greenhouse gases emitted by cars, trucks, factories, power plants and farms are carbon dioxide, methane and nitrous oxide. Gases enter the upper atmosphere and hang there, trapping heat and causing global warming.
The good news is that carbon dioxide, methane and nitrous oxide do not live forever in the atmosphere. Eventually, they are destroyed or absorbed by plants, oceans, soil and rocks on the Earth’s surface.
But humans generate such huge emissions that new greenhouse gases enter the atmosphere much faster than old emissions are destroyed or absorbed. That is why gases accumulate in the atmosphere extremely quickly, especially in the last 50 years.
Different greenhouse gases take different time to decompose or be absorbed. Nitric oxide is retained in the atmosphere for about 100 years. Carbon dioxide can last for hundreds or even thousands of years.
“If we get rid of all emissions tomorrow, carbon dioxide will fall very, very slowly,” said James Butler, director of global monitoring at the National Oceanic and Atmospheric Administration’s Earth Research Laboratory. “It would take thousands of years to come out.”
Then there is methane, which changes the shape of the greenhouse gases. Methane represents only a small part of the greenhouse gases emitted each year. But once in the atmosphere, methane is extremely good at capturing heat from the sun, making it far more powerful than carbon dioxide in the short term.
Fortunately, methane decomposes relatively quickly. If humans stop emitting greenhouse gases, it will only take about 100 years to dissipate excess methane into the atmosphere, Butler said.
Here’s the problem: When methane decomposes, it can be converted to carbon dioxide. Both gases have carbon at their center: methane has bonded hydrogen atoms and carbon dioxide has oxygen atoms. With the decomposition of methane, hydrogen atoms are replaced by oxygen from the air. One greenhouse gas is replaced by another.
Life with warmth
The White House plan aims to reduce the use of fossil fuels to slow the atmospheric accumulation of greenhouse gases and the projected rate of global warming. Electricity will come from renewable sources such as wind and solar, cars and trucks will run on electricity, and factories will capture their emissions before entering the atmosphere. Trains and buses would be more efficient and ubiquitous. The new buildings will require less energy for heating and cooling.
Economists are already seeing signs that the economy is beginning to move to the next generation of cleaner and cheaper energy. The price of wind and solar energy has fallen sharply and energy-efficient vehicles are becoming increasingly popular.
But because greenhouse gases linger in the atmosphere for so long, scientists warn that reducing emissions will not be enough to protect everyone. Many people will also need help adapting to a hotter Earth.
“Imagine riding a train and heading right to a rock,” Hsiang said. If you apply the brakes too late, some of the cars will go over the edge.
The train is humanity. The rock represents deadly heat waves, forest fires, floods and droughts. So far, the United States has pressed the brakes. Now the United States is committed to pushing harder and trying to stop the train before it passes over the edge.
But the scale is set, says Xiang. “If we don’t slow things down fast enough, there are large regions of the world, very different people, that will be severely affected by the changes that continue to develop in the next century.”
Those most at risk include poor people, people who manage, people who work outdoors, and people who live in places that are already dangerously hot or prone to flooding. “These are the people who are sent off the rock,” Xiang said.
The Biden administration acknowledged that reducing emissions in the United States was not a complete response to climate change. The proposed infrastructure bill will include money to help US cities avoid damage and health impacts from storms, fires and heat waves.
And other countries are also seeking US adaptation assistance. As a newly restored country that has signed the Paris Climate Agreement, the United States is once again in the background for the $ 2 billion the Obama administration promised the Green Climate Fund.
The fund exists to help pay for climate projects in poorer countries that are already suffering from the effects of global warming, including adaptation projects such as the construction of sea walls and the transition to drought-resistant crops.
Earlier this year, White House climate envoy John Kerry said the United States would “keep up” with the Obama-era promise, but did not say whether it would increase contributions in the future as it emits more cumulative greenhouse gases than any other is another country.