Last week’s United Nations report on the health of the planet and the services it provides made for very uncomfortable reading. It shows that humans are making a complete mess of things, destroying biodiversity and     1    ecosystems. The pressure we are placing on the planet through overexploitation of resources on land, sea and air is driving the Earth and its human cargo towards a catastrophic(灾难性的)end, one that will trigger a global mass     2    which may make the planet uninhabitable.

The sad thing is we can see this crisis     3    our way but don’t seem to be able to do anything to save ourselves. This isn’t just about climate change, although those who deny the human impact on climate may use similar arguments in a(n)     4    to undermine(暗中破坏)the UN report.

It may be portrayed(描述)as exaggeration or bad science, or an issue of dispute among the international team of scientists who compiled the report. Fake news. There is no dispute about the facts     5    , that at least a million species are now in serious decline or facing extinction. These species could disappear and if things continue as they are, another million more could follow.

We are shortening our odds     6    if you look at the UN report. We are damaging the web of life and the way that species interconnect and interact, but we don’t know to what end or how the damage we are causing will impact on ourselves. Are we     7    that humans would survive a runaway greenhouse effect for example? Would we be able to use technology to help us survive? But what of the social unrest(动荡)and migration that would follow a failure of crops in dry,     8    climates?

One direction we cannot turn to for help is planet Earth itself. It too evolves over geological[地质(学)的]time as the     9    that make up its surface ride across the planet. It makes mountains and creates inland seas. It kicks off environment-changing volcanoes and lets geology alter its surface. It doesn’t care if a species pollutes its oceans with plastic or tears down oxygen-     10    forests. It is life, in whatever form, that instead must adjust to accommodate changes in the planet that arise through natural causes or careless intervention.

A good grilling

As they reopen after lockdown, many restaurants are firing up their barbecues. Diners appreciate food grilled over glowing charcoal embers, but the     1     residents often do not. Pollution levels near restaurants can be     2     higher than average, because of emissions from kitchens. With the increasing popularity of indoor barbecuing, it is a problem that is set to get worse.

The researchers tested a commercial grill,     3     with the sort of multistage filtering system used in many — though by no means all — restaurants. Apart from typical pollutants and particulate matter, they also discovered polycyclic aromatic hydrocarbons (多环芳烃). These cancer-causing chemicals are mainly produced by the incomplete combustion (燃烧) of     4     and oil-based sauces. The researchers estimated that if their half-a-square-metre grill was used for nine hours a day, it would release between 400 and 500 kilograms of fine and ultrafine particulate matter into the air every year. With many restaurants using 2.5-square-metre grills 16 hours a day, the level of pollution from most commercial    5     would be much higher.

The researchers are investigating which extraction systems best protect all the people     6     such as the restaurant employees. Taller chimneys are one option. But Dr Aleysa, an expert in combustion technology, suspects they would just     7     the pollution elsewhere. The results of these tests will be published next year.

Meanwhile, Dr Aleysa’s team have come up with their own solution: a new kind of grill, which they reckon can cut pollutants by 90%. Dr Aleysa is reluctant to go into     8    . But the basic idea is that before being released to the outside, the fumes are sucked back down through the embers and into a combustion zone, where hydrocarbons and odour compounds are fully burnt. That lessens the need for expensive extraction systems and fiddly filters that must be     9     cleaned.

An industrial partner is keen to put the grill into production. It could go on sale by the middle of next year. It will cost a bit more than a standard grill, says Dr Aleysa. But he believes that would be offset by lower     10     costs. Better air quality around restaurants would be welcome. But the big test will be whether chefs believe the new grill can produce that same barbecue flavour.