Recent extreme weather events, youth activism and political attention to proposals such as the green New Deal are making climate change a top-tier issue in the 2020 presidential race. A major United Nations climate summit in September and bipartisan conversations on carbon pricing are attracting increased media coverage with dedicated town halls and forums being organized around the issue.
Additionally, president Trump’s, rollback of environmental regulation and promised to pull out of the Paris agreement, has created a backlash and generated energy around climate action. The last four years have been the warmest in the 139 years that NOAA has been keeping records.
The Intergovernmental Panel on Climate Change states that with 95 percent certainty, the current warming trend is the result of human emissions of greenhouse gases into the atmosphere, mostly carbon dioxide from burning fossil fuels.
Many of the impacts that climate models predict in a warming world are happening right now, including sea level rise, stronger cycles of rain and drought and migration of plants, animals and people to different areas in reaction to temperature change or resource scarcity.
The climate has certainly changed in the past with ice ages and warmer periods. These are mostly associated with small variations in the Earth’s orbit around the Sun, which changed the amount of solar energy the earth receives.
However, the changes we are seeing today are happening much faster than anything in the geological record. Remember that there’s, an important difference between weather and climate climate is the trend of weather over time and space cold spells still happen, even in a climate that is warming overall.
In fact, a warming climate may result in more cold spells in some areas as larger patterns of atmospheric circulation. Like the Jetstream change, the United States is a large contributor to global greenhouse gas emissions and has key leadership role to play in a transition towards lower carbon energy sources.
The United States is the world’s. Second largest emitter of green house gasses responsible for about 15 % of global emissions. In 2018, China overtook the United States to become the largest emitter in 2006.
U.S. emissions have been mostly declining since 2005, although they rose somewhat last year. The United States also played a crucial role in designing the Paris agreement, which brought nearly all of the world’s.
Countries together in a commitment to fight climate change. U.S. reengagement in the process will be important to the Paris agreement. Success to encourage more ambitious goals over time and to assist countries that lack the resources to reduce their own emissions.
The world will not be able to prevent the worst effects of climate change unless all countries with large ambitions are on board, including countries lower on the income scale such as India and China.
Policy must push for change in the easier sectors. Now, while encouraging research and pilot scale deployment of new technologies to deal with the most difficult sectors, several policy tools are available.
Carbon pricing is a policy that economists love for its ability to encourage the least expensive ways of reducing emissions. A carbon tax or a cap and trade system where emitters buy and trade permits to emit greenhouse gases would both serve the purpose.
The challenge is that tax is a dirty word in American politics. Setting the talks high enough to make a difference would be politically difficult and any tax or cap-and-trade system will require action from Congress.
Direct regulation is another policy tool available to reduce emissions. Numerous existing regulations impact greenhouse gas emissions, including federal efficiency, standards for vehicles and appliances and state and local renewable energy requirements.
Regulation offers more certainty and results than carbon pricing, but tends to be less economically efficient, since it does not allow trade-offs amongst sectors of the economy. The tax code can also be used to encourage emissions reductions, including credits for developing renewable energy or carbon capture and storage tax credits, encourage investment, but need to be adjusted over time as cost fall as we are seeing today in renewable energy.
Finally, government can directly fund research and development that is to early-stage or too risky for the private sector to take on. The federal government spends more than six billion dollars annually on energy and environment research, with an additional 11 billion spent on general science, and these amounts have been largely consistent in recent years.
In reality, all of these methods are needed. No single policy is enough to create such a deep change in the economy. The keys to success for any policy are ambition and consistency. Recent years have seen a complete about-face and climate policy, as president Trump has rolled back Obama.
Administration efforts to reduce emissions, industry and consumers need consistent signals to change an ambitious bipartisan legislation from Congress is central to creating lasting change. To learn more about this and other issues check out our voter vitals at Brookings.edu/policy2020.