1 . The number of weather-related disasters has increased by five times over the past 50 years, the latest report by the World Meteorological (气象) Organization (WMO) said on September. However, thanks to improved early warning systems and disaster management, the number of death from these hazards (危险) has been almost three times less.

According to the WMO, from 1970 to 2019, weather, climate and water hazards accounted for 50 percent of all disasters. Among the top 10 hazards that led to the largest loss of human life during this period were droughts, storms, floods and extreme temperatures. However, deaths fell from over 50, 000 in the 1970s to less than 20, 000 in the 2010s.

“Weather, climate and water extremes are increasing and will become more frequent and severe in many parts of the world as a result of climate change,” says WMO Secretary-General Petteri Taalas.

“That means more heat waves, drought and forest fires such as those we have observed recently in Europe and North America. We have more water vapor in the atmosphere, which is worsening extreme rainfall and deadly flooding. The warming of the oceans has affected the frequency and area of existence of the most intense tropical storms.”

“Economic losses are increasing as exposure increases. But behind the statistics lies a message of hope. Improved multi-hazard early warning systems have led to a significant reduction in deaths. Quite simply, we are better than ever before at saving lives,” Taalas said.

4 . In his new book The Journeys of Trees, science writer Zach St. George explores an extremely slow migration(迁 徙), as forests move inch by inch to more hospitable places. As old trees die and new ones grow up, the forest is—ever so slightly—moving, he writes. “Through the fossils(化石) that ancient forests left behind, scientists can track their movement. They move back and forth across continents, like migrating birds or whales.”

This has happened over thousands of years, and climate change tends to be the driving force—pushing and pulling forests around the globe. Of course, today, climate change is speeding up, and trees can’t keep pace. Take Califomnia: It’s getting hotter and drier and scientists estimate that before too long, Joshua Tree National Park may not be able to sustain Joshua trees. Zach St. George describes a similar threat to Sequoia National Park, during California’s long and severe drought a few years back.

Scientists worried that maybe Sequoia National Park would no longer be the place for giant sequoias. St. George thinks at some point we will lose these ancient trees and we will have to think about what we do with the places, and do we plant new ones somewhere else? This is known as “assisted migration”—humans planting trees in other places where they’re more likely to grow well. But this process carries risks—people can accidentally introduce insects and diseases to new places, where they may wipe out entire native populations. So, St. George writes, there’s a debate among conservationists and foresters today: Should humans help the trees escape?

“I think there are going to be instances where people are probably going to step in and help species move to places where they’ll be more suitable in the future,” St. George says. “And I met a lot of people in the process who have felt sorry about what has been lost and what will be lost—and are still continuing to try and do good and work in the moment for small things.”

5 . On September 7, 1991, the costliest hailstorm (雹暴) in Canadian history hit Calgary’s southern suburbs. As a result, since 1996 a group of insurance companies have spent about $2 million per year on the Alberta Hail Suppression Project. Airplanes seed threatening storm cells with a chemical to make small ice crystals fall as rain before they can grow into dangerous hailstones. But farmers in east-central Alberta — downwind of the hail project flights — worry that precious moisture (水分) is being stolen from their thirsty land by the cloud seeding.

Norman Stienwand, who farms in that area, has been addressing public meetings on this issue for years. “Basically, the provincial government is letting the insurance companies protect the Calgary-Edmonton urban area from hail,” Mr. Stienwand says, “but they’re increasing drought risk as far east as Saskatchewan.”

The Alberta hail project is managed by Terry Krauss, a cloud physicist who works for Weather Modification Inc. of Fargo, North Dakota. “We affect only a very small percentage of the total moisture in the air, so we cannot be causing drought.” Dr. Krauss says. “In fact, we may be helping increase the moisture downwind by creating wetter ground.”

One doubter about the safety of cloud seeding is Chuck Doswell, a research scientist who just retired from the University of Oklahoma. “In 1999, I personally saw significant tornadoes form from a seeded storm cell in Kansas,” Dr. Doswell says. “Does cloud seeding create killer storms or reduce moisture downwind? No one really knows, of course, but the seeding goes on.”

Given the degree of doubt, Mr. Stienwand suggests, “It would be wise to stop cloud seeding.” In practice, doubt has had the opposite effect. Due to the lack of scientific proof concerning their impacts, no one has succeeded in winning a lawsuit against cloud-seeding companies. Hence, private climate engineering can proceed in relative legal safety.

8 . Steven Stein likes to follow garbage trucks. His strange habit makes sense when you consider that he’s an environmental scientist who studies how to reduce litter, including things that fall off garbage trucks as they drive down the road. What is even more interesting is that one of Stein’s jobs is defending an industry behind the plastic shopping bags.

Americans use more than 100 billion thin film plastic bags every year. So many end up in tree branches or along highways that a growing number of cities do not allow them at checkouts(收银台). The bags are prohibited in some 90 cities in California, including Los Angeles. Eyeing these headwinds, plastic-bag makers are hiring scientists like Stein to make the case that their products are not as bad for the planet as most people assume.

Among the bag makers’ argument: many cities with bans still allow shoppers to purchase paper bags, which are easily recycled but require more energy to produce and transport. And while plastic bags may be ugly to look at, they represent a small percentage of all garbage on the ground today.

The industry has also taken aim at the product that has appeared as its replacement: reusable shopping bags. The stronger a reusable bag is, the longer its life and the more plastic-bag use it cancels out. However, longer-lasting reusable bags often require more energy to make. One study found that a cotton bag must be used at least 131 times to be better for the planet than plastic.

Environmentalists don’t dispute(质疑) these points. They hope paper bags will be banned someday too and want shoppers to use the same reusable bags for years.

9 . This fall, students at the University of Massachusetts found a new menu at their dining commons: the “diet for a cooler planet” menu. This meant herb-roasted lamb, raised with a carbon-friendly approach. It included sweet potatoes that had been picked from a local farm’s field post-harvest. The options were plant-heavy, locally grown, and involved little to no packaging.

“We wanted to let students participate in climate action by making choices about their food,” says Kathy Wicks, sustainability director for UMass Dining. The university is not alone in this effort. Increasingly, American consumers and institutions are thinking about how their food choices factor into climate change. For many, small choices at the grocery store, dining hall, and restaurant can feel more accessible than big-ticket options like buying a fuel-efficient car or installing home solar panels.

Small changes in dietary habits may make a big difference. Climate activists often target fossil fuels and transportation systems, but studies point to the food system as a significant contributor to global warming. According to Project Drawdown, a research organization that evaluates climate solutions, the way food is grown, transported, and consumed accounts for about a quarter of the world’s greenhouse gas emissions. Beef is a regular target. “If, on average, Americans cut a quarter pound of beef per week from their diet, it’s like taking 10 million cars off the road a year,” says Sujatha Bergen, director of health campaigns for the Natural Resources Defense Council. Food waste ranks third among climate solutions. While much waste occurs before consumers are involved — food left on the field or “chucked” because it does not fit appearance standards, Americans also throw out a lot of food they have purchased: about $ 1,600 worth a year per family of four.

“People are beginning to understand that their food choices make a big impact on climate,” says Megan Larmer, director of regional food at the Glynwood Center for Regional Food and Farming in New York. But, she cautions substantial change will need to come from the whole food system.

10 . By the end of the century, if not sooner, the world’s oceans will be bluer and greener thanks to a warming climate, according to a new study.

At the heart of the phenomenon lie tiny marine microorganisms(海洋微生物) called phytoplankton. Because of the way light reflects off the organisms, these phytoplankton create colourful patterns at the ocean surface. Ocean colour varies from green to blue, depending on the type and concentration of phytoplankton. Climate change will fuel the growth of phytoplankton in some areas, while reducing it in other spots, leading to changes in the ocean’s appearance.

Phytoplankton live at the ocean surface, where they pull carbon dioxide(二氧化碳) into the ocean while giving off oxygen. When these organisms die, they bury carbon in the deep ocean, an important process that helps to regulate the global climate. But phytoplankton are vulnerable to the ocean’s warming trend. Warming changes key characteristics of the ocean and can affect phytoplankton growth, since they need not only sunlight and carbon dioxide to grow, but also nutrients.

Stephanie Dutkiewicz, a scientist in MIT’s Center for Global Change Science, built a climate model that projects changes to the oceans throughout the century. In a world that warms up by 3℃, it found that multiple changes to the colour of the oceans would occur. The model projects that currently blue areas with little phytoplankton could become even bluer. But in some waters, such as those of the Arctic, a warming will make conditions riper for phytoplankton, and these areas will turn greener. “Not only are the quantities of phytoplankton in the ocean changing. ” she said, “but the type of phytoplankton is changing.”

And why does that matter? Phytoplankton are the base of the food web. If certain kinds begin to disappear from the ocean, Dutkiewicz said, “it will change the type of fish that will be able to survive.” Those kinds of changes could affect the food chain.

Whatever colour changes the ocean experiences in the coming decades will probably be too gradual and unnoticeable, but they could mean significant changes. “It’ll be a while before we can statistically show that the changes are happening because of climate change,” Dutkiewicz said, “but the change in the colour of the ocean will be one of the early warning signals that we really have changed our planet.”