Global warming

Over the past century, the Earth’s average temperature has swiftly increased by about 1 degree Celsius (1.8 degrees Fahrenheit). The evidence is hard to dispute. It comes from thermometers and other sensors around the world. But what about the thousands of years before the Industrial Revolution, before thermometers, and before humans warmed the climate by releasing heat-trapping carbon dioxide from fossil fuels? Back then, was Earth’s temperature warming or cooling? Even though scientists know more about the most recent 6,000 years than any other multimillennial interval, studies on this long-term global temperature trend have come to contrasting conclusions. To try to resolve the difference, we conducted a comprehensive, global-scale assessment of the existing evidence, including both natural archives, like tree rings and seafloor sediments, and climate models. Our results, published Feb. 15, 2023, suggest ways to improve climate forecasting to avoid missing some...

Several major airlines have pledged to reach net-zero carbon emissions by midcentury to fight climate change. It’s an ambitious goal that will require an enormous ramp-up in sustainable aviation fuels, but that alone won’t be enough, our latest research shows. The idea of jetliners running solely on fuel made from used cooking oil from restaurants or corn stalks might seem futuristic, but it’s not that far away. Airlines are already experimenting with sustainable aviation fuels, including biofuels made from agriculture residues, trees, corn and used cooking oil, and synthetic fuels made with captured carbon and green hydrogen. United Airlines, which has been using a blend of used oil or waste fat and fossil fuels on some flights from Los Angeles and Amsterdam, recently announced plans to power 50,000 flights a year between its Chicago and Denver hubs using ethanol-based sustainable aviation fuels by 2028. The airline also launched a US$100 million fund on Feb...

Some hurricanes are remembered for their wind damage or rainfall. Others for their coastal flooding. Hurricane Helene was a stew of all of that and more. Its near-record-breaking size, storm surge, winds and rainfall together turned Helene into an almost unimaginable disaster that stretched more than 500 miles inland from the Florida coast. At least 230 people died across Florida, Georgia, South Carolina, North Carolina, Tennessee and Virginia as Helene flooded towns, destroyed roads and bridges and swept away homes. In Florida, Helene’s storm surge caused damage along hundreds of miles of coast. As residents there cleaned up debris, another dangerous hurricane was headed their way. Some of the same areas hit hard by Helene on Sept. 26, 2024 – including Tampa Bay and Cedar Key – were forecast to see more flooding and an even higher storm surge in Tampa Bay from Hurricane Milton, expected to make landfall as early as Oct. 9. The majority of Helene’s vic...

What’s the cheapest, quickest way to reduce climate change without roiling the economy? In the United States, it may be by reducing methane emissions from the oil and gas industry. Methane is the main component of natural gas, and it can leak anywhere along the supply chain, from the wellhead and processing plant, through pipelines and distribution lines, all the way to the burner of your home’s stove or furnace. Once it reaches the atmosphere, methane’s super heat-trapping properties render it a major agent of warming. Over 20 years, methane causes 85 times more warming than the same amount of carbon dioxide. But methane doesn’t stay in the atmosphere for long, so stopping methane leaks today can have a fast impact on lowering global temperatures. That’s one reason governments at the 2022 United Nations climate change conference in Egypt focused on methane as an easy win in the climate battle. So far, 150 countries, including the United States...

Leer in español Something significant is happening in the desert in Egypt as countries meet at COP27, the United Nations summit on climate change. Despite frustrating sclerosis in the negotiating halls, the pathway forward for ramping up climate finance to help low-income countries adapt to climate change and transition to clean energy is becoming clearer. I spent a large part of my career working on international finance at the World Bank and the United Nations and now advise public development and private funds and teach climate diplomacy focusing on finance. Climate finance has been one of the thorniest issues in global climate negotiations for decades, but I’m seeing four promising signs of progress at COP27. Getting to net zero – without greenwashing First, the goal – getting the world to net zero greenhouse gas emissions by 2050 to stop global warming – is clearer. The last climate conference, COP26 in Glasgow, Scotland, nearly fell apart o...