2 . Depleted forests are never out of the headlines, but do you know that several tech-led techniques are being employed to improve reforestation and bring these lungs of nature, a key source of oxygen in the atmosphere, back to life? Nature news website, Mongabay, recently devoted a mini-series to exploring the newest technological solutions that support worldwide reforestation efforts, but not without pointing out that reforestation efforts often have weaknesses.

This Mongabay review speaks frankly about the blemishes of labor-intensive reforestation efforts as poor planning leads to underreported tree planting outcomes. For example, perhaps trees were planted where they didn’t suit the chosen habitats.

According to Mongabay, the challenge is to match rising demand for restoration with ecologically sound, scalable (可扩展的) reforestation methods. “Scale is the biggest challenge to restoration and reforestation projects worldwide,” said Charlotte Mills, chief ecologist at AirSeed Technologies in Australia. The good news is that new tech solutions can help make tree planting at scale easier, faster and more successful.

For instance, solar-powered, seed-planting robots, able to plant up to 600 trees in a morning, are being carried out by conservationists working in the Peruvian Amazon. Drones (无人机) are employed to drop seeds in precise areas, especially at remote and difficult-to-access sites. One company operating them is Mast Reforestation, a Seattle-based one working on North America’s conifer (针叶树) forests destroyed by logging, insects and wildfire.

The Globe and Mail reports on how Canadian start-up, Flash Forest, uses drones that fire seeds at a high speed into the soil. It has a great goal to go beyond changing forestry to slow down climate change and finally conserve ecological diversity.

Sending people out on field monitoring to assess the health of new trees which take years to mature is time-consuming and costly. Here, satellites are stepping up to provide large-scale data sets over time on how huge reforested sites are going. Food giant Nestle announced in April 2023 that it’s working to monitor its reforestation efforts long-term using satellites.

4 . Solar stills (蒸馏器) provide a clever and simple means of purifying dirty or salty water, but they work at a rather slow rate. A new material has been shown to boost their performance, and it’s made from fruit waste which would otherwise be thrown away.

In its most basic form, a conventional solar still consists of a basin of undrinkable water that is set beneath a cover. The water evaporates (蒸发) as it’s heated by the sun, condensing (凝结) on the inside surface of the cover. That condensation—which is pure, clean water-drops down the cover and is collected in a separate container for drinking. In order to warm the dirty/salty water at a faster rate, scientists have developed materials that float on its surface, transforming sunlight into heat. They commonly use carbon obtained from coal.

To seek a less costly and more environmentally-friendly alternative, Prof. Edison and colleagues at Singapore’s Nanyang Technological University looked to something that is free for the taking—fruit waste. More specifically, the scientists tried out coconut peels, orange peels and banana peels.

In a simple carbonization process, the fruit waste was heated at 850℃for a few hours, and mixed with a kind of chemical substance. Doing so transformed the fruit waste into a new material which has a very highlight-to-heat transforming efficiency.

When tested in a small solar still, this new material proved to be very effective at transforming sunlight into heat, causing the dirty/salty water to evaporate much more rapidly. And because the material is full of holes, the waters team is able to rise right through it, subsequently condensing on the inside of the still’s cover.

Prof. Edison and his team found material obtained from the coconut peels worked best, as it transformed sunlight to heat with an efficiency rate of 94%. They are now developing the technology further, and are seeking industry partners to help with its commercialization.

Earth Day is an annual celebration that honors the achievements of the environmental movement and raises awareness of the need to protect Earth’s     1     (nature) resources for future generations.

The first Earth Day     2     (celebrate) on April 22, 1970. Environmental activism during the 1960s inspired Gaylord Nelson, a US official from Wisconsin, to create a national celebration uniting the environmental movement.     3     the help of Denis Hayes, a graduate student at Harvard University, Nelson organized the first Earth Day,     4     (educate) participants (参与者) on the importance of environmental conservation.     5     (attend) by 20 million people across the United States, the event strengthened support for making laws.

In 1990, Hayes organized a global Earth Day,     6     was observed by some 200 million people in more than 140     7     (country). Since then, Earth Day has been international.

By the early 21st century, Earth Day’s many activities included raising awareness of a number of growing environmental concerns,     8     (especial) the threat of global warming and the need for clean, renewable energy sources.

The theme for Earth Day 2023 is “Invest (投资) in Our Planet”. This year’s theme is designed     9     (persuade) businesses, governments, and citizens around the world of the need to invest in our planet to improve our environment and give our descendants     10     better and safer future.

6 . ICT is short for computers, phones and other information and communications technology. Lancaster University researchers examined previous scientific studies that calculated the ICT industry’s total greenhouse gas emissions (排放), which they say were put as somewhere between 1.8% and 2.8%.

But these estimates likely fall short, they warn. In fact, ICT’s true proportion (比例) is between 2.1% and 3. 9%—greater than the global aviation industry’s proportion of 2% —they say.

ICT not only consists of smartphones and computers, but televisions, mobile network equipment and data centres. It also includes the more recent trendy digital technologies such as Blockchain, the Internet of Things (IoT) and artificial intelligence (AI).

The problem with many popular devices (设备) is that they contain liquid crystal display (LCD) panels. Every time these devices are made, greenhouse gases are emitted into the atmosphere. Also, abandoned electronic devices are sometimes burnt, releasing carbon dioxide (CO₂) and harmful chemicals into the air.

The new study has been conducted by experts at Lancaster University, who point out that ICT’s share of emissions could stop humanity from achieving net zero by 2050—one of the targets of the UK government.

The researchers recognise that several of the world’s technology giants have made statements on reducing their climate footprint, like Apple and Facebook. However, they argue that many of these promises are not ambitious (宏大的) enough.

In the paper, the experts say it’s often been cited that ICT will lead to greater efficiencies (高效) across many other sectors, leading to decrease in net greenhouse gas emissions. However, the researchers argue that historical evidence proves the opposite. They say that over the years, as ICT has become more efficient, ICT’s footprint has taken up a greater proportion of global emissions. This could be partly due to the fact that increased efficiencies result in increased demand.

7 . For hundreds of years, America’s wilderness has been reduced due to growing cities, leaving outdoors lovers like hunters with fewer chances. By around 1900, too much hunting drove America’s deer nearly into extinction (灭绝), less than a half-million deer, from 45 million in 1450.

Law-makers began to make rules to protect deer and keep ecological balance (生态平衡). And it did make a big difference. By 2000, the deer population had come up to 38 million. Those days, millions of deer lived side by side with humans and could freely find enough food resources.

Gradually, the number of deer was increasing too rapidly, which was not good for both the animals and people. City hunting plays an important role in keeping ecological balance, particularly in places where the animals sometimes cause major problems.

“City deer hunting is a management practice used in many cities and suburban areas across the United States,” says Jason Andrews, program manager of the Urban Deer Hunt in Cedar Rapids, Iowa. In the early 2000s, a high number of car accidents were caused by deer. And there was also significant vegetation degradation (植被退化) in many cities. Many possible solutions were researched by the city government. Some suggested hunting deer and other wild animals, but others were against that practice.

In the end, researchers determined that the most effective and sustainable (可持续的) population management solution would be hunting with bows. “City deer hunting is popular in cities that have too many wild deer as well as wooded areas,” says Andrews. “In Cedar Rapids, all parts of the city have right habitats to keep deer population, thus hunting is allowed. I must note that hunting is only allowed on private lands. No parks or any other public grounds can be hunted.”