2 . Shop Sustainably

If you have to name one thing that contributes most to your ecological footprints, you may say the energy you use at home, or your car’s emissions.     1     Knowing this can make your grocery shops more planet-friendly. Here is what you can do to help shop sustainably.

●    2     Using those is a great first step. If you get some, do remember to fill them with your purchases. When you adapt yourself to reusing them, then you’ll cut your consumption of single-use plastic bags even further.

●Avoid unnecessary packing. Buy loose fruit and vegetables instead of pre-packaged produce, and avoid products that contain multiple single packages or double packaging, like grain in a box and a bag. Consider switching from tea bags and coffee pods to tea leaves and ground coffee.     3    

●Go organic when you can. In addition to the benefit organic farming has to insect biodiversity, it’s also considered more sustainable and better for the environment.     4    Choosing free-range or Marine Stewardship Council-certified products also encourages environment- and animal-friendly food production.

●Buy seasonal and native products.     5     So you can avoid buying goods that have travelled long distances to reach your plate. As well as opting for local goods, depending on where you live, in the supermarket, you can also buy directly from the source at farmers’ markets.

5 . When lightning caused fires around California’s Big Basin Redwoods State Park north of Santa Cruz in August 2020, the fire spread quickly. Mild fires strike coastal redwood (红杉) forests about every decade. The giant trees resist burning thanks to the bark (树皮), up to about 30 centimetres thick at the base, which contains acids. Their branches and needles are normally beyond the reach of flames. But this time flames shot through the top of 100-metre-tall trees, burning the needles. “It was shocking,” says Drew Peltier, a tree expert at Northern Arizona University. “It really seemed like most of the trees were going to die.”

Yet many of them lived. In a paper published yesterday in Nature Plants, Peltier and his colleagues help explain why: The survivors use long-held energy reserves—sugars that had been made from sunlight decades earlier—and poured them into buds (芽) that had been lying dormant (休眠的) under the bar k for centuries.

“This is one of those papers that challenges our previous knowledge on tree growth,” says Adrian Rocha, an ecosystem ecologist at the University of Notre Dame. “It is amazing to learn that carbon taken up decades ago can be used to sustain its growth into the future.” The findings suggest redwoods have the tools to cope with big fires driven by climate change, Rocha says. Still, it’s unclear whether the trees could cope with the regular infernos that might occur under a warmer climate environment.

The fire in 2020 was so intense that even the top branches of many trees burned and their ability to photosynthesize (光合作用) went up in smoke along with their pine needles. Trees photosynthesize to create sugars and other carbohydrates (碳水化合物), which provide the energy they need to grow and repair tissue. Trees do store some of this energy, which they can call on during a drought or after a fire. Although the redwoods have sprouted (长出) new growth, Peltier and other forest experts wonder how the trees will cope with far less energy from photosynthesis, given that it will be years before they grow as many needles as they had before the fire. “They’re alive, but I would be a little concerned for them in the future.”

6 . Climate change is causing more areas to turn into deserts. This issue is affecting the lives of 250 million people as land that used to be good for farming becomes dry and unproductive. Around one-third of the world’s land is impacted, including regions in Africa, southern Europe, Asia and America.

Sand to Green is a Moroccan company that can transform a patch of desert into a sustainable (可持续的) and profitable plantation in five years, according to Wissal Ben Moussa, its co-founder and chief agricultural officer. The solution is using agroforestry (农林业)to create a new kind of agriculture that is sustainable and that can be resilient (有适应力的) in front of climate change.

The system can be set up close to any source of salty water, which Sand to Green cleans using energy from the sun. It then grows different types of fruit trees and plants together in the same area—a method called mixed planting—and waters the plants’ roots directly with the cleaned water, to reduce water loss to the air. The soil is regenerated using what Sand to Green calls “green manure”, a mixture that includes compost, biochar(生物炭)and microorganisms that help the soil “wake up”. Biochar is a form of charcoal that can help dry soil hold on to water.

In a five-hectare trial in southern Morocco that’s been running since 2017, Sand to Green has tried out a variety of plants in search of the best performers. Among the intercropping herbs (草本植物) that have been successfully trialed are rosemary, geranium, vetiver and citronella, which Ben Moussa describes as “very low-maintenance and very high-profit”.

Sand to Green is now working to scale up to a 20-hectare commercial site, also in southern Morocco. It says a site of that size would cost around $475,000 to set up and would start bringing financial returns in about five years.

According to Ben Moussa, with this system they create biodiversity, which means better soil, healthier crops and a bigger yield. The plantation can generate 1.5 times more yield, thus making more money than a farm that grows only one type of crop in the same space.

7 . “The era of global warming has ended and the era of global boiling has arrived,” the UN secretary general, Antonio Guterres, said after scientists confirmed July 2023 was the world’s hottest month on record.

“Humanity is in the hot seat,” Guterres told a press conference on Thursday. “For vast parts of North America, Asia, Africa and Europe, it is a cruel summer. For the entire planet, it is a disaster. And for scientists, it is clear that humans are to blame. Climate change is here, it is terrifying, and it is just the beginning. The era of global warming has ended; the era of global boiling has arrived.”

Guterres urged politicians to take swift action. “The air is unbreathable, the heat is unbearable, and the level of fossil fuel profits and climate inaction is unacceptable. Leaders must lead. No more hesitancy, no more excuses, and no more waiting for others to move first. There is simply no more time for that.”

“It is still possible to limit global temperature rise to 1.5℃and avoid the very worst of climate change but only with dramatic, immediate climate action. We have seen some progress, but none of this is going far enough or fast enough. Accelerating temperatures demand accelerated action.”

The WMO secretary general, Petteri Taalas, said, “The need to reduce greenhouse gas emissions is more urgent than ever before. Climate action is not a luxury but a must.”

Other climate scientists confirmed the findings. Karsten Haustein at Leipzig University found the world was 1.5℃ hotter in July 2023 than in the average July before industrialisation.

Marina Romanello, a climate and health researcher at University College London, said, “We have data showing how the very foundations of health are being undermined by climate change. But we still have time today to turn the tide and to ensure a liveable future for us and our children.”

8 . Nature has the power to alter an element’s identity with time and space. This is evident by the transformative effect Britain’s deep coal mines have been showing after decades of being one of the biggest reasons for pollution. Now, they’re being employed to supply green energy to the town of Gateshead. The town is the first place to experience something like this in the country, but the success of the phenomenon has encouraged the authorities to apply it to other towns.

In 2021, coal was just producing 2% of electricity in the UK. Most of the electricity in the country is being supplied through oil and gas. This has resulted in massive abandoned coal mines all across the country. As years went by, these mines were flooded with water, making it a source of geothermal（地热的） energy, which is used to generate heat and electricity. Gateshead hosts such a mine in its town, whose council, therefore, launched a mine water project in March 2023.

The authorities put in a large central heat pump in the mine. Mine water can often sit with a temperature of 45℃. The water is then pumped using appliances to home heat pumps. The process increases the temperature further. The water then goes ahead and warms up the interior space and home water supply. After the heat from the water has been used, it’s sent back to the mine where it again goes through the same process. The project has been successful in supplying low-carbon heating to 350 high-rise buildings, a college and several office buildings.

“Recovering heat from mine water below the ground within abandoned coal mines provides an exciting opportunity to generate a low-carbon secure supply of heat, benefitting people living or working in buildings on the coalfields,” said Gareth Farr, head of heat and by-product innovation at the Coal Authority.

The water resources through the mines are estimated to be two billion cubic meters or half the amount of water in Loch Ness. Farr added, “With many millions of people living upon abandoned coalfields in Great Britain, the potential for mine water heat could be significant.”

9 . In recent years, the popular idea of reducing carbon footprints by eating locally to cut down food miles has come under close examination. However, a recent study published in Nature Food indicates that global food miles might account for as much as 20 percent of food-related emissions, a significantly higher percentage than previous estimations. This statement begs the question: Are food miles more significant than we initially believed?

Food miles represent the distance food travels from production to consumption, with previous studies suggesting that the emissions from these miles are tiny compared to the emissions produced during the food growing process. For instance, producing one kilogram of beef generates almost 99 kg of CO₂, while apples only produce 0.4 kg per kilogram. If the goal is to minimize dietary carbon footprints, it would be more beneficial to choose foods with lower overall carbon footprints, even if they have to travel a distance. Therefore, reducing meat and dairy intake could prove to be a more effective strategy.

The recent study doesn’t contradict (相矛盾) this conclusion. The reason why the reported proportion is higher is that the calculation includes all transport involved, including the transportation of fertilizers, farm equipment, and pesticides (杀虫剂). Hannah Ritchie, a researcher at the University of Oxford, suggests that a term other than “food miles” would be more appropriate to avoid any confusion. If the study had followed the standard definition of food miles, the per-centage would drop to 9 percent, which corresponds more closely with the 4 to 6 percent found in prior research.

Moreover, the study theorizes that even if all food was produced in the countries where it is consumed, the reduction in emissions would only be 1.7 percent overall. This is due to the fact that a larger proportion of food would be transported by road rather than by sea, with trucks producing higher emissions per ton of cargo than ships.

“So, overall, the bottom line is still that what you eat has a much bigger impact on emissions than the distance that food has to travel to reach you,” said Ritchie.

10 . As the Earth turns, its rotational axis (自转轴) naturally move a bit. Anything from ocean currents, to shifting molten rock under the crust, to the melting (融化) of glaciers caused by climate change can cause the axis to drift (飘移). Water stored in artificial lakes and seasonal changes in atmospheric winds can play a role as well.

But global warming isn’t the only human-caused factor moving the planet’s axis as some of us believe. A new study estimates that between 1993 and 2010, the pumping of groundwater and the resulting sea-level rise caused the axis lo drift by about 2.6 feet. “Every mass moving around on the surface of the Earth can change the rotational axis,” said Ki-Weon Seo, a geophysicist at Seoul National University.

In the study, the researchers used a computer model to look at the effects of different factors on the shift of the axis. When they didn’t include groundwater removal in their model, their predictions did not match the level of shift that scientists have observed. But when they look into account the massive amount of pumped water — which totaled more than two trillion tons between 1993 and 2010 ― their model fit the real-world observations. From this analysis, the researchers estimate that the axis is moving 1.7 inches per year due to groundwater removal. Of the factors the study looked at, pumping groundwater was the second-largest contributor to the axis drifting, behind the melting Greenland ice sheet.

The paper calls attention to just how much water humans have pumped, as Clark Wilson, a geoscientist at the University of Texas, tells Science. “The precise number doesn’t matter really. What matters is that the volume is so huge that it can impact the polar drift of the Earth,” he says. “Groundwater removed from sites at the Earth’s midlatitudes (中纬度), such as in the U.S. and India, has a large impact on polar drift, compared with extraction at the equator or the poles. However, most of the pumping has occurred in these high-impact zones, causing the water removal to have a bigger effect on the axis,” says Wilson.