(Bloomberg) -- Last year was the hottest in recorded history, and this year could be even hotter. In the US, more than 3 million Americans are already climate migrants and a record-setting year for billion-dollar disasters means an increasing number of people are feeling the impacts of climate change. 

Perhaps it’s no surprise, then, that a recent survey of more than 1,000 Americans found 1 in 10 are experiencing climate anxiety or depression. It also found those who believe climate change is happening outnumbered those who don’t five to one, and over half of the survey’s participants said they understand climate change is mostly caused by humans. Importantly, the analysis found Americans have questions about climate change, especially about how to address it.

“The issue has advanced in public awareness and engagement,” said Anthony Leiserowitz, director of the Yale University Program on Climate Change Communication, which undertook the analysis with the George Mason University Center for Climate Change Communication. “We’re seeing this growth in questions of what can the US do to reduce global warming and the nations of the world.” 

That represents a major shift. In the 2011 iteration of the research group's survey, 51% of Americans said they would ask scientists whether climate change was a hoax, compared to 39% in 2023.

While Americans are increasingly curious about how to solve climate change, as well as its root causes, one thing was missing from the Yale and George Mason analysis: the answers. On that front, Bloomberg Green has you covered. 

Is global warming a hoax?

Let’s get this out of the way: No. More than 99% of scientists agree the world is getting hotter, and burning fossil fuels is driving the rise in temperatures. Scientists also agree that the climate has never changed this fast in human history, a direct result of the excess greenhouse gas emissions being pumped into the atmosphere. 

What causes global warming?

Burning fossil fuels is the primary cause of global warming. Doing so emits carbon dioxide and other greenhouse gases that act as a blanket in the atmosphere, trapping heat. Other human activities like deforestation, manufacturing and transportation release warming gases into the atmosphere, too. Today, there is more CO2 in the atmosphere than there has been in at least the last 2 million years. 

How do we know global warming is happening?

Scientists have known CO2 has a warming effect since the Industrial Revolution, and they have a plethora of tools to monitor how the global average temperature is changing. Climate scientists use thermometers placed around the world to study local temperatures over time. Satellites can also measure temperature from space. From these along with other forms of data, scientists construct a global average temperature record. 

Researchers can also compare that to the past climate by relying on other resources. Coral reefs, tree rings and ancient glacial ice are some of the resources scientists can use to examine the climate centuries or even millennia ago. That includes the temperature as well as ice extent, sea levels and precipitation. Together, these analyses show a planet rapidly warming.

Read more: Near Record Jump in CO2 Emissions This Year Risks Climate Goal

How do we know that warming is caused mostly by human activities, not natural changes in the environment?

Beyond the well-established relationship between CO2 and warming, we know that human activities have emitted a lot of CO2 since the 1850s: Burning fossil fuels have unleashed over 1.5 trillion tons of CO2, according to Climate Central. 

Over that period, the planet has warmed by roughly 1.2C (2.2F), the hottest it’s been in at least 125,000 years. Scientists can use computers to examine the climate with and without the impact of rising CO2 and other greenhouse gases. Without that increase, the Earth’s surface temperature would be virtually unchanged. 

That’s led scientists to the conclusion that global warming is “unequivocally” caused by human activities. What’s more, greenhouse gases have warmed the planet far more than shifts in sunspots, land use or volcanic eruptions.

What can countries do to reduce global warming? What about the US specifically?

It starts with an array of policies focused on reducing carbon emissions, including taxes, standards and incentives, according to an analysis from the National Academies of Sciences, Engineering and Medicine. The study provides 80 recommendations for how the US can cut emissions. Among them are local and regional incentives for adopting clean energy, strengthening disclosure rules for companies’ decarbonization policies and increasing electric vehicle charging stations at airports and ports. 

In the US, 2022’s Inflation Reduction Act (IRA) passed in 2022 and 2021’s bipartisan infrastructure law both offer tax incentives to people who, among other things, buy electric vehicles or install heat pumps. They also contain incentives for companies to do everything from capturing carbon to making green hydrogen. 

Read more: Electric Cars Are Driving China Toward the End of the Age of Oil

These policies are a step in the right direction, but they’re not a panacea. The IRA will reduce greenhouse gas emissions by up to 42% by 2030, according to researchers at the Rhodium Group. Still, it is not enough to meet the US pledge of a 50% to 52% reduction under the Paris Agreement.  

What can I do to reduce global warming?

While the biggest changes will need to come from governments and companies, there are things individuals can do to fight global warming. The biggest are switching to renewable energy at home, driving an electric vehicle (or no vehicle at all) and reducing meat consumption — especially beef.  

Read more: There’s One Good Way to Think About Your Carbon Footprint

These choices are no stand-in for reining in carbon pollution from the fossil fuel industry, power plants and other major industrial emitters. And to ensure more people have access to make these types of switches, governments will likely need to provide support to make the transition equitable. 

How much will it cost the US to reduce global warming?

Trillions of dollars. 

Getting the US to net-zero emissions by 2050 — the Biden administration’s goal — would require a $30 trillion investment in the energy system, according to BloombergNEF researchers. 

The IRA allocated $369 billion to combat climate change via tax credits and direct subsidies. Since President Joe Biden took office in 2021, the private sector has invested $350 billion in clean energy, according to John Podesta, the White House senior advisor on clean energy and innovation. In other words, investments so far are essentially a down payment on a much more costly multi-decade project to decarbonize the country. But those investments are well worth it compared to the alternative.

The estimated financial damages related to global warming have totaled almost $7 trillion over the past 30 years, according to Bloomberg Intelligence senior ESG climate analyst Andrew John Stevenson. Since 2016, the average cost has been $500 billion a year, or 2% of the US GDP. And with climate change set to worsen, those costs are likely to rise in the coming decades unless actions are taken to reduce risks.

What harm will global warming cause? 

It’s not a question of “will.” Climate change is wreaking havoc today. 

“Climate change is already harming our health and wellbeing, harming our ecosystems, harming our livelihoods, [and] harming our economy,” said Kristie Ebi, a professor of global health at the University of Washington’s Center for Health and the Global Environment. 

Last year, the US suffered 25 billion-dollar weather disasters, including wildfires in Hawaii, flooding in Vermont and Hurricane Idalia hitting Florida. The US was hit with a billion-dollar disaster every three weeks between 2018 to 2022, according to the Fifth National Climate Assessment published late last year. 

Read more: Melting Greenland Has Lost 1 Trillion Tons More Ice Than Thought

Sea levels are rising faster than they have in the past 100 years, and are expected to rise another 11 inches by 2050. New York City might see once-in-a-century flooding events every year. Almost 50 million people could experience temperatures that human bodies are not equipped to survive, according to a 2018 study from Lancet Planetary Health. 

Research also shows that exposure to dangerous conditions will be unequal. People in poor regions are more likely to die from extreme heat compared to their wealthy peers due to lower investments in air conditioning and infrastructure.

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