Unfortunately, everything else they were warning about has only got worse since 1992. So now almost ten times as many scientists—15,364 to be precise—have come together to give us a “second notice.” With signatories including the likes of Jane Goodall and E.O. Wilson, this is the most scientists to ever co-sign a published journal article. And there’s no reason to feel good about what they’re telling us.

Broadly speaking, there are two big trends that are freaking out the experts. The first is climate change, exacerbated by the greenhouse gases we encourage by burning fossil fuels, cutting down forests, and farming the way we do (particularly for meat production). The second is the mass extinction event that is taking place, threatening many life forms that we take for granted today.

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The root cause, the scientists said on Monday, is that there are too many of us, and our consumption is out of control:

“By failing to adequately limit population growth, reassess the role of an economy rooted in growth, reduce greenhouse gases, incentivize renewable energy, protect habitat, restore ecosystems, curb pollution, halt defaunation, and constrain invasive alien species, humanity is not taking the urgent steps needed to safeguard our imperiled biosphere.”

But let’s go back to the good news. We managed to stop putting a hole in the ozone layer by phasing out the chemicals that were causing it (cholofluorocarbons) and, as a result, the hole is closing and there are millions fewer cases of skin cancer than there would otherwise have been.

“The rapid global decline in ozone-depleting substances shows that we can make positive change when we act decisively. We have also made advancements in reducing extreme poverty and hunger,” the scientists wrote, adding that we’ve made progress in lowering fertility rates too—largely by improving girls’ and women’s education.

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Now, according to the scientists, which have formed a group called the Alliance of World Scientists, our policy-makers need to push hard on other fronts. And so do we, as consumers and citizens.

Their list of recommendations is extensive. Let’s start with those that we as individuals can take to heart:

1. Fertility

We need to stop having so many kids, ideally limiting our reproduction to “replacement level at most.” That means one or two children, on average.

2. Diet and food waste

We need to stop wasting so much food, given the environmental impacts of food production. As the worst environmental impacts come from farming ruminants such as cattle and sheep, the scientists also recommend a shift towards “mostly plant-based foods.”

3. Buy green

We need to pay more attention to the things we buy and invest in, to make sure that they “encourage positive environmental change.”

4. Nature appreciation

People are increasingly living in cities, so they need to retain some connection with nature. The experts recommend “increasing outdoor nature education for children, as well as the overall engagement of society in the appreciation of nature.”

And here are the recommendations for policy-makers:

5. Environmentally aware economies

We need to revise our economies “to reduce wealth inequality and ensure that prices, taxation, and incentive systems take into account the real costs which consumption patterns impose on our environment,” the scientists said, adding: “We must recognize, in our day-to-day lives and in our governing institutions, that Earth with all its life is our only home.”

6. More nature reserves

We need to establish a lot more “well-funded and well-managed” reserves to protect species in the sea and fresh water, in the air and on land.

7. Stop wiping out ecosystems

We need to stop converting forests, grasslands and other native habitats, and we need to restore plant communities that have already been slashed, “particularly forest landscapes.” Forests, lest we forget, aren’t just essential homes to many species; they also absorb greenhouse gases. Also, we need to re-wild certain areas.

8. Stop wiping out animal species

We’re undergoing the sixth mass extinction event in Earth’s history. To fight it, we need to fight poaching and the “exploitation and trade of threatened species.”

9. Green technologies

Fossil fuel-based energy production needs to stop getting subsidized, and we need massive investment in and adoption of renewable energy sources.

One notable aspect of the letter was the fact that it avoided spelling out the doomier scenarios that we face if we don’t change tack.

A separate paper published on Monday proposed what the authors said was a more accurate way of measuring global warming than those we currently use. And unfortunately, they said, it looks like our existing estimates have been underplaying how much warming is currently taking place, leaving us less time than we thought to achieve the targets set out in the Paris Climate Agreement.

Policy-makers from around the world are currently meeting in Bonn, Germany, under the auspices of the United Nations Climate Change Conference (COP 23). The U.S. did not send a formal delegation, but it did send delegates to a side event where they were derided for promoting “clean coal” as a way to reduce carbon emissions.