2 . In the rich countries of the West, the electric vehicle revolution is well underway. Climate-conscious consumers drive Teslas or Polestars for reasons of morality and fashion. Poorer countries are also experiencing a wave of electrified trend. In Bangladesh, electric three-wheeler taxis, known as tuk-tuks, are rapidly replacing gas-powered ones on the streets. Such electric vehicles are climate friendly, cost effective, and help reduce air pollution.

Yet a glance under the hood (引擎盖) of these vehicles reveals a poisonous secret: each tuk-tuk runs on five massive lead-acid batteries, containing almost 300 pounds of lead in total. Every year and a half or so, when those batteries need to be replaced and recycled, about 60 pounds of lead leak into the environment. Battery recycling, often at small-scale unregulated factories, is a highly profitable but deadly business.

Lead is dangerous, and any exposure to it is harmful to human health. Lead that has entered the environment hurts people on an extraordinary scale. The numerous ways lead enters air, water, soil, and homes across the developing world — and the enormous damage it does to human health, wealth, and welfare — causes one of the biggest environmental crises in the world yet receives little attention.

The World Bank estimates that lead kills 5. 5 million people per year, which would make it a bigger global killer than AIDS, malaria, diabetes, and road traffic deaths combined. On top of the shocking deaths, the social burden of lead poisoning is extraordinary, as is its contribution to global inequality — our research on the cognitive effects of lead poisoning suggests that it may explain about one-fifth of the educational achievement gap between rich and poor countries.

But unlike many challenges faced by developing countries, lead poisoning is a problem that is fixable with some attention and a relatively modest financial investment. Better monitoring, research, and rules can help protect children all over the world from the dreadful effects of lead poisoning and reduce the massive global costs it brings.

Go Recycling

No one looking at the state of Earth in 2023 can be in any doubt that we are facing three serious environmental problems: climate problem, loss of biodiversity (生物多样性) and pollution of air, soil and water. To solve the problems, we increase the use of electric cars,     1     greener eating and reduce plastic use. However, sometimes these solutions can be opposite to the expected goals. For instance, creating space for biofuel crops to give off fewer pollutants and greenhouse gases can, in fact,     2     increase the cutting down of trees. That means in most cases solutions aiming at one problem each time are     3     to be effective. And, what is perhaps lacking is a(n)     4     of how interlinked these problems are.

We should realize that a key     5     linking all the three problems is waste. The root cause of global warming is CO₂, a waste gas. The seas are polluted by plastic and other waste products. We     6     forests, among other things, to grow more food — much of which goes to waste.

A shocking figure lies at the heart of our special report on our world — of the more than 100 billion tons of things that humans use each year, hardly 10% is recycled. That makes it obvious a full-range war on waste should be paid     7     attention. The situation requires our speedy moving away from the way of thinking — “take, make, throw” — towards a more recyclable one, which means we should begin     8     the products and when they reach the end of their useful lives, they can be recycled.

Solving the three problems calls for a huge transition with joint efforts. Governments must take the lead by introducing laws with the purpose of rewarding green practices, such as the     9     of waste. Industries can reduce, re-use and recycle wherever possible, and     10     themselves with suppliers and the like-minded to realize recyclable business models.

It is perhaps the most ironic symbol of the life on our planet. The Amazon is the world’s largest and most bio-diverse tropical rainforest and a huge trap for carbon dioxide. The harms of _________ in this vital resource are old news. But now, the time on the clock is running out. It seems that the world’s biggest rainforest is about to turn into the world’s biggest environmental _________. “We are about to collapse,” says Luciana Gati at Brazil’s National Institute for Space Research. “We are in a(n) _________, we need action now.”

Gati has spent years _________ the Amazon from the air. She believes we are as little as five years from a point of no return, where rainforest begins to turn into dry land. It is also the point at which billions of tons of carbon would be _________ into the atmosphere. “It’s a nightmare,” she says.

That nightmare situation is the well-known Amazon _________ point, where the ecosystem can no longer cope with the damage of the forest cutting. Like a domino game, one brick falling will _________ the whole tower to collapse in a heap.

Warnings that this is approaching have now taken on extreme urgency. The rate of deforestation has increased sharply and is fast approaching the theoretical _________. In September, a group of more than 200 experts, including Gatti, released an assessment of the situation. The conclusion: we are on the _________ of disaster.

Scientists first began to seriously worry about a potential Amazon tipping point in about 2000, when some studies warned that a combination of climate change and deforestation could cause the rainforest to __________.

A few years later, a team of Brazilian scientists put numbers on it. They __________ that in central, southern and eastern parts of the Amazon, a loss of 40% of the forest cover from pre-industrial levels, or 3°C warming would reduce rainfall so much that the rest of the forest would die of __________ and turn into a dry land in less than a decade.

The scientists have since __________ that prediction, partly due to the global warming that has happened since 2000. The Amazon is already 1.2°C warmer than it was in pre-industrial times and is warming three times faster than the global __________. At that rate of warming, between 20 and 25% deforestation would be enough to dry up the land and destroy the Amazon completely.

“Either way, we would be wise not to exceed 20%”, says a scientist, “for the commonsense reason that there is no point in __________   the precise point of limit by tipping it.”

Urban Trees Are Threatened by Climate Change

By 2050, about three-quarters of the species will be at risk as a result of climate change, a study has found. Cities around the world may need to start planting different types of trees and shrubs that can     1     warmer and drier conditions.

“By ‘at risk’, we mean these species might be     2     stressful climatic conditions,” says Manuel Esperon-Rodriguez at Western Sydney University in Australia. “Those trees are likely to die.”

City trees have many benefits, from making urban spaces look beautiful and providing a refuge for wildlife to keeping places up to 12°C cooler than they would otherwise be in summer. Losing tree     3     would lead to cities becoming even hotter as the planet heats up.

To     4     the threat, Esperon Rodriguez and his colleagues used database called the Global Urban Tree Inventory to work out the conditions required by 3100 tree and shrub species currently grown in 164 cities worldwide. The researchers then looked at how these conditions would be affected by climate change under medium-emissions scenario known as RCP 6.0.

By 2050, 76 per cent of these species will be at risk from rising     5     temperatures and 70 percent from decreasing rainfall, the team concludes.

The study doesn’t take account of       6     urban growth, which could warm cities even faster. Nor does it take account of greater weather     7     caused by climate change, or the effects of pests and diseases. Warmer conditions are allowing more pests, such as bark beetles, to survive winters as well as to reproduce faster in summer, greatly increasing their     8    .

“Our     9     have scientific basis,” says Esperon-Rodriguez. There are some things that can be done to help trees survive. The best strategy is to choose tough species when     10     trees or planting new ones, the team concludes.