According to a major new report on climate change released on Monday, nations need to move away from fossil fuels much faster to retain any hope of preventing a perilous future on an overheated planet.
The goal of limiting global warming to 1.5 degrees Celsius, or 2.7 degrees, is the goal of the Intergovernmental Panel on Climate Change, a body of experts convened by the United Nations.
That is the threshold beyond which scientists say the dangers of global warming grow considerably. Humans have heated the planet by burning fossil fuels since the 19th century.
The report found that holding warming to 1.5 degrees Celsius would require nations to collectively reduce their planet-warming emissions by 43 percent by 2030 and to stop adding carbon dioxide to the atmosphere altogether by the early 2050s. Current policies by governments are only expected to reduce global emissions by a few percentage points this decade. Fossil fuel emissions rebounded to near-record highs last year after a brief dip as a result of the coronaviruses.
The report, which was approved by 195 governments and lays out strategies that countries could pursue to halt global warming, comes as Russia's invasion of Ukraine has caused oil and gas prices to spike. In the United States and Europe, leaders are focused on shoring up domestic fossil fuel supplies to avoid painful price spikes and energy shortages, even if that means increasing emissions in the short term.
Climate scientists say there is no margin for delay if the world wants to hold global warming to manageable levels.
Jim Skea, an energy researcher at Imperial College London who helped lead the report, said that every year that you let pass without going for urgent emissions reductions makes it more and more difficult.
Even if the goal becomes impossible, it will still be worthwhile for countries to cut emissions as quickly as possible. The U.N. panel has found that every additional rise in global temperatures increases the perils that people face around the world, such as water scarcity, malnutrition and life-threatening heat waves.
Even if we go beyond 1.5, that doesn't mean we throw up our hands and despair.
Scientists say that global warming will largely come to a halt once humans stop adding heat-trapping gases like carbon dioxide to the atmosphere. According to the report, if nations reach net zero emissions by the early 2070s, they could likely stop global average temperatures from rising more than 2 degrees Celsius, or 3.6 degrees Fahrenheit, above preindustrial levels.
There are some positives in the new report. Over the past decade, many nations have adopted more ambitious climate policies, scaled back plans for new coal plants and expanded their use of renewable energy through subsidies and regulations. Although emissions from fossil fuels are still growing worldwide, the rate of growth slowed in the 2010s, compared with the 2000s, the report said, and humanity now has a better shot at avoiding some of the worst-case global warming scenarios.
The report said that clean energy technology has advanced quickly. The cost of solar panels and batteries for electric vehicles has fallen by 85 percent since 2010, while the cost of wind turbines has fallen by half.
The shift away from fossil fuels will require nations to do a lot more. The report said that governments and companies would need to invest three to six times as much as they currently spend to encourage clean energy and cut emissions over the next decade.
In terms of deaths, displacement and damage, the cost of inaction is substantial. In the United States last year, floods, fires, and other disasters related to weather and climate caused an estimated $145 billion in damages. The agency said that the levels of disasters were getting high.
Glen Peters of the Center for International Climate Research in Norway, who contributed to the report, said that reducing emissions substantially is less painful than he thought.
The report looks at dozens of strategies proposed by scientists and energy experts to help nations make the transition.
The power plants that generate electricity for homes and factories would need to be cleaned first. It means using more energy sources such as wind, solar, nuclear, and hydropower. Coal and natural gas plants would either need to shut down or install carbon capture technology that can trap emissions and bury them underground. High costs have slowed the take off of such technology.
The next step would be to use clean electricity instead of fossil fuels in the transportation, industry and other segments of the global economy. Cars powered by gasoline could be replaced with electric vehicles. Electric heat pumps could replace gas-burning furnaces. Electric furnaces that melt scrap could be used instead of burning coal.
Nations could take steps to reduce their total energy demand. Expanding public transit, upgrading insulation, and making factories more energy efficient are some of the things that could be done. The report states that demand-side policies could help cut emissions by as much as 70 percent by the end of the century.
Many economic activities can be easily plugged in. Most airplanes have batteries that are too heavy. Cement and glass require extreme heat and burn coal or gas. The report said that new fuels and industrial processes will have to be developed for those emissions.
Around a fifth of global greenhouse gases are emissions from agriculture. Global meat production, which emits methane and carbon dioxide, and is causing rampant rainforest destruction, is one of the issues that needs to be dealt with.
Wetlands and forests are powerful natural stores of carbon dioxide, which makes sparing them from destruction a highly effective and economical way to mitigate warming, said a World Wildlife Fund scientist who helped write the report.
The report warned that humanity is unlikely to eliminate all of its planet warming emissions. Billions of tons of carbon dioxide will have to be removed from the atmosphere by midcentury. The report warned that one strategy could be to plant more trees. Devices that suck carbon out of the air are still immature.
The report acknowledges the huge challenges ahead. There would be job losses and financial dislocation if coal, oil and gas projects were stopped. Some climate solutions leave less land for growing crops or raising livestock to feed a world population that keeps growing.
In the developing world, governments still need to expand access to electricity and modern cooking fuels for hundreds of millions of the lowest income people, which might only be possible in the short term by burning more fossil fuels. Efforts to cut emissions deeply have run up against two longstanding issues: high costs and over stretched governments.
If technology could solve the problem completely, the problem could have been solved decades ago, according to a researcher who helped write the report.
Fatima Denton, director of the United Nations University Institute for Natural Resources in Africa and another author of the report, said there is strong political will in many developing nations to tackle climate change. She said that greater financial support from wealthy nations is critical, partly as a matter of fairness and historical responsibility, as Western countries that got rich by burning fossil fuels are now telling poor nations that they cannot do the same.
You are telling them to leave their resources in the ground when they have always seen them as a way to more capitalism, more wealth, and more prosperity.
Last year, China's leader said that his country would stop building new coal plants overseas, a major step towards promoting green energy in the developing world. China is digging up and burning more coal to keep electricity flowing despite the economic disruptions of the war in Ukraine and the coronaviruses. China is the top greenhouse gas emitting country.
Cecilia Han Springer, a China said that the recent crises show that if decarbonization happened earlier, China, as well as other regions, would have been more resilient to some of these shocks.
India's government has increased energy efficiency in homes and factories, given farmers solar-powered water pumps, and helped promote the rapid construction of solar farms. Efforts to expand clean energy will not be financially sustainable because the country's state-run electric utilities are in fragile fiscal health.
The way governments, businesses and even societies work is needed to slash emissions.