Last weekend, I took part in a forest clean-up activity. It was organized by Green Hope, an organization devoted to protecting forests.起初，我不想参加，    1    but then I thought, “What if nobody goes?”

Our team leader, Joe, took us to a forest outside the city. I was sad to find rubbish everywhere.     2    There was a “No littering” sign at the entrance to the forest, but that didn’t stop people from throwing their rubbish on the ground. Joe divided us into two groups:    3     one group cleaned up the north side of the forest, and the other the south side. After several hours’ work,看到森林比以前看起来要干净些，我们很开心    4    It was absolutely worth our effort!

There will be another clean-up activity in the greenbelt next Saturday. You can call Joe and sign up    5     if you would like to help. Everyone who takes part in the activity will receive a medal. I’ll join you too if I have time.

6 . With one in eight people worldwide threatened by a heat wave in South Asia that’s already taken close to 100 lives, it’s time we should recognize that the climate crisis is a health crisis.

This is not an isolated issue. In South Africa, recent floods took over 400 lives, and in place like Colombia, health and food security are at risk as floods displace communities and trigger disease outbreaks. According to the WHO, a quarter of a million people are expected to die every year from climate change between 2030 and 2050 if we do nothing about it.

Climate change affects the determinants of health——clean air, safe drinking water, sufficient food, and secure shelter. According to the recent IPCC Climate Change Report, climate change has harmful impacts on human health, ranging from death from extreme events to illness from increasing temperatures. And for the first time ever, the report includes mental health as a key area impacted by the climate crisis, noting that climate change has affected physical and mental health of people globally.

These irreversible (不可逆转的) damages force us to rethink climate and health. However, when you think about it as a whole, the crisis is amazingly complex. In places like Egypt, people need air-conditioners to survive the120-plus degree days. But more AC means more greenhouse gases. So, we need to consider economic development, renewable energy, and reduction of pollutants that are literally poisoning our planet.

The good news is that we are making progress. With funding from the Global Environment Facility Special Climate Change Fund, WHO supported local governments to pilot climate change adaptation efforts to protect human health. In Barbados, community-based public health campaigns supported the safe use of wastewater. In Bhutan, the government has advanced its ability to predict climate-sensitive infectious diseases. And in China, three pilot cities have implemented a heat-health warning system.

Millions of lives hang in the balance. It’s time we should step up and make climate-health action a global priority. This is our investment in planet Earth, in future generations and in a better world.

7 . After taking a few steps back, Hadj Benhalima rushed toward the building, pushed himself upward with his foot against the wall and stretched out his arm. At the peak of his jump, he flipped off a light switch, and the bright lights of a nearby barbershop went off immediately.

This is what Hadj and his friends have been doing for the past two years: swinging around Paris and switching off wasteful shop signs at night, in an effort to fight against light pollution and save energy. And they are all enthusiastic about Parkour — a sport that consists of running and jumping over urban obstacles.

While climbing other people’s property to turn off their lights may strike some as a form of trespassing (非法入侵), the Parkour athletes insist their activities are only about enforcing seldom-respected rules.

More than a decade ago, Paris City Hall issued orders requiring stores to turn off all signs and window displays from 1 am to 6 am, but they are widely ignored with little consequence. “for 10 years there has been no follow-up, no control, no punishment,” said Anne-Marie Ducroux, the head of the National Association for the Protection of the Sky and the Night Environment.

That is why Hadj and his friends have taken matters into their own hands. The group often gathers in the so-called Golden Triangle neighborhood, in western Paris, which is the center of French luxury.

Enforcing the orders in place of the authorities certainly enters a legal grey area. But the Parkour athletes say all the police officers they have met during their rounds have allowed their action — as long as it causes no damage.

And it seems that their efforts have produced the desired result, because Hadj says he has noticed that in recent months, several shops have stopped leaving their lights on after his group targeted them. He hopes others will follow suit. “At least, I’ll sleep better,” he said.

8 . After years of severe drought combined with climate change, the water level in Lake Powell, the second largest reservoir on the Colorado River, has dropped to just 24% of capacity. It is continuing to decline to levels not seen since the reservoir was first filled in the 1960s.

In an effort to improve the shrinking reservoir, the federal government announced that it will hold back a large quantity of water this year to reduce risks of the lake falling below a point at which Glen Canyon Dam would no longer generate electricity.

“Today’s decision reflects the truly unexpected challenges facing the Colorado River Basin and will provide operational certainty for communities and businesses that rely on the Colorado River,” Tanya Trujillo, the federal Interior Department’s assistant secretary for water and science, said in a statement announcing the measures.

It is the first time the U. S. Bureau of Reclamation has called its authority to change its operations in this way at Glen Canyon Dam on the Arizona-Utah border. The agency said the plan is intended to protect infrastructure at the dam and its ability to generate hydropower. It will ensure that water supplies continue to be available for the nearby city of Page, Arizona, and the Navajo Nation.

The plan is supposed to reduce the risks of Lake Powell falling to extremely low levels. The measures will include releasing about 500,000 acre-feet of water from Flaming Gorge Reservoir, which is located upstream, and leaving an additional 480,000 acre-feet in Lake Powell by reducing the volume of water released from Glen Canyon Dam.

“What’s needed now, urgently, is for federal and state water managers to work in partnership with other related parties, to take the steps necessary to build confidence in the long-lasting management of the Colorado River,” Pitt said. “This will require intensive and dedicated resources to develop and implement plans that put water demands into balance with supplies.”

9 . In recent years, studies have suggested how the bisphenol A (BPA) in some food-packaging plastics has been linked to various health problems including heart disease and developmental difficulties in children. Scientists are thus developing a more harmless alternative, and it’s made from tomato waste which would otherwise be got rid of.

However, BPA is still widely used in the plastic coatings which are applied to the inside of metal food packaging such as cans. These smooth waterproof coatings help protect the metal from corrosion (腐蚀), plus they keep the food from sticking to the inside of the container.

Building on previous studies, an international team has researched a type of agricultural waste known as tomato pomace. This material typically consists of tomato skins, seeds and stems, which are left over after the fruits have been processed for use in foods such as sauces or juices. Ordinarily, the pomace is simply dumped in a landfill, burned, or at best composted. It may also be used in animal feed, although it doesn’t have much nutritional value.

The scientists started by drying tomato pomace — first in the sun for three days, then in a 60℃ oven for 16 hours — after which they grounded it into a powder. That powder was subsequently mixed with a sodium hydroxide solution (溶液), which was then heated at 100℃ for four hours. After repeatedly filtering that solution to remove the sodium hydroxide, the researchers were left a lipid. That lipid was then mixed into an ethyl alcohol solution which was sprayed onto samples of some metal. Once the spray had dried and the samples had been heated in a 200℃ oven for 10 to 60 minutes, the result was a polymerized lacquer coating which proved to be very effective at protecting the metal.

The scientists now plan on testing the coating on actual cans. “We would take tomato sauce, and other foods that are usually sold in cans, and we would sterilize them, put them in tins and check if they withstand real conditions,” said a scientist.

10 . A new study by researchers at the University of British Columbia (UBC) and the University of Victoria has shown that common levels of traffic pollution can damage human brain function in only a matter of hours.

“For many decades, scientists thought the brain may be protected from the harmful effects of air pollution,” said senior study author Dr. Chris Carlsten. “This study, which is the first of its kind in the world, provides fresh evidence supporting a connection between air pollution and cognition.”

For the study, the researchers briefly exposed 25 healthy adults to diesel exhaust (柴油废气) and filtered air at different times in a laboratory setting. Brain activity was measured before and after each exposure using functional magnetic resonance imaging (fMRI).

The researchers analyzed changes in the brain’s default mode network (DMN), a set of inter-connected brain regions that play an important role in memory and internal thought. The fMRI revealed that participants had decreased functional connectivity in widespread regions of the DMN after exposure to diesel exhaust, compared to filtered air.

“We know that altered functional connectivity in the DMN has been associated with reduced cognitive performance and symptoms of depression, so it’s concerning to see traffic pollution interrupting these same networks,” said Dr. Jodie Gawryluk, a psychology professor at the University of Victoria and the study’s first author. “While more research is needed to fully understand the functional impacts of these changes, it’s possible that they may impair (损害) people’s thinking or ability to work.”

Notably, the changes in the brain were temporary and participants’ connectivity returned to normal after the exposure. Dr. Carlsten assumed that the effects could be long lasting where exposure is continuous. He said that people should be mindful of the air they’re breathing and take appropriate steps to minimize their exposure to potentially harmful air pollutants like car exhaust.