According to the new article Oxford Open Climate ChangeThe strategies that humanity must pursue to mitigate climate change must involve more than reducing greenhouse gases. This is stated in an analysis of climate data led by researcher James Hansen.

Scientists know that infrared (greenhouse) gases warm the Earth’s surface, and that excess greenhouse gases vary naturally as well as through human activities. Roger Revell, one of the first scientists to study global warming, wrote in 1965 that industrialization meant humans were conducting a “great geophysical experiment” by burning fossil fuels, which added carbon dioxide (CO).₂) into the air. Carbon dioxide has reached levels not seen in millions of years.

climate sensitivity

A long-standing issue concerns how much global temperature will increase for a given increase in CO2.₂. A study published in 1979 by the United States National Academy of Sciences concluded that CO doubled.₂ The presence of ice sheets in the atmosphere is likely to cause global warming of 1.5–4.5°C. This was a wide range, with the added uncertainty of delayed warming caused by Earth’s vast oceans.

This new paper reassesses climate sensitivity based on improved paleoclimate data and finds that climate is more sensitive than generally assumed. Their best guess is a doubling of CO₂ Global warming is 4.8°C, well above the UN Intergovernmental Panel on Climate Change’s best estimate of 3°C.

aerosols

The authors also concluded that much of the warming expected from greenhouse gases over the past century was offset by the cooling effect of man-made aerosols, which are tiny particles in the air. Aerosols have decreased since 2010 due to reduced air pollution in China and global restrictions on aerosol emissions from ships. This reduction in aerosols is good for human health, as particulate air pollution kills several million people a year and affects the health of many more.

But the reduction in aerosols is now beginning to reveal the greenhouse gas warming hidden by aerosol cooling. Authors have long called aerosol cooling a “Faustian bargain” because as humanity eventually reduces air pollution, the payoff comes in the form of increased warming.

This new paper predicts that after 2010, global warming will accelerate above the level of natural climate variability. The rate of global warming, which was 0.18°C per decade between 1970 and 2010, is predicted to increase to at least 0.27°C per decade after 2010. As a result, global warming will exceed 1.5°C in this decade and 2°C in the next two decades.

Policy

In the final chapter, Hansen describes his perspective, based on decades of experience trying to influence government policy. First, he believes it is possible to achieve a rapid and gradual reduction in CO emissions. ₂ It calls for increasing the local carbon tax, along with introducing a border tax on products from countries that do not charge a carbon tax, and supporting modern nuclear energy as well as renewable energy sources.

Second, he argues that the West, which is primarily responsible for climate change, should work with developing countries to help them achieve climate-friendly energy pathways for all.

Third, Hansen believes that despite such efforts, global warming will reach dangerous levels; He argues that we should also conduct research and development for interim, targeted actions to address the Earth’s currently massive energy imbalance.

Ten years ago, Hansen stated that the Earth’s energy balance was disrupted by 0.6 W/m2.² (watts per square meter). Much more energy comes from incoming energy (absorbed sunlight) than outgoing energy (thermal radiation into space). This excess, which is the direct cause of global warming, is equivalent to 400,000 Hiroshima atomic bombs per day, and most of this energy goes into the oceans. The imbalance has now doubled to approximately 1.2 W/m2, mainly due to the decrease in aerosols.².

This massive imbalance is the direct cause of accelerating global warming and increasing melting of polar ice caps; This would likely halt ocean water circulation and lead to a significant, rapid rise in sea level later this century.

The article argues that such action would be necessary to prevent the greater geographic transformation that would occur in the absence of such action. Potential measures include the introduction of stratospheric aerosols, where volcanoes provide suitable but inadequate test scenarios, and the spraying of salty ocean water by autonomous sailboats in areas susceptible to cloud formation.

Hansen argues that young people are focusing on a major problem emerging in Western democracies, especially the United States: “The ideal of one person/one vote has been replaced by the ideal of one dollar/one vote.” argued Hansen. “Special financial interest groups (e.g. fossil fuel industry, chemical industry, forestry industry, food industry) have the right to buy off politicians. They are causing the climate to spiral out of control, environmental toxicity to destroy insects, including pollinators, mismanagement of forests, and agriculture to lose nutrition.” and no wonder it was designed for profit rather than prosperity.”

“We live on a planet with a climate of delayed response, which is a recipe for intergenerational injustice,” Hansen continued. “Young people need to understand this situation and understand what needs to be done to ensure a bright future for themselves and their children.” Source