By the end of 2024, nearly 200 nations will have met at three conferences to address three problems: biodiversity loss, climate change and plastic pollution.
Colombia will host talks next week to assess global progress in protecting 30% of all land and water by 2030. Hot on its heels is COP29 in Azerbaijan. Here, countries will revisit the pledge they made last year in Dubai to “transition away” from the fossil fuels driving climate breakdown. And in December, South Korea could see the first global agreement to tackle plastic waste.
Don’t let these separate events fool you, though.
“Climate change, biodiversity loss and resource depletion are not isolated problems” say biologist Liette Vasseur (Brock University), political scientist Anders Hayden (Dalhousie University) and ecologist Mike Jones (Swedish University of Agricultural Sciences).
“They are part of an interconnected web of crises that demand urgent and comprehensive action.”
Let’s start with the climate.
“How hot is it going to get? This is one of the most important and difficult remaining questions about our changing climate,” say two scientists who study climate change, Seth Wynes and H. Damon Matthews at the University of Waterloo and Concordia University respectively.
The answer depends on how sensitive the climate is to greenhouse gases like CO₂ and how much humanity ultimately emits, the pair say. When Wynes and Matthews asked 211 authors of past reports by the Intergovernmental Panel on Climate Change, their average best guess was 2.7°C by 2100.
“We’ve already seen devastating consequences like more flooding, hotter heatwaves and larger wildfires, and we’re only at 1.3°C above pre-industrial levels — less than halfway to 2.7°C,” they say.
There is a third variable that is harder to predict but no less important: the capacity of forests, wetlands and the ocean to continue to offset warming by absorbing the carbon and heat our furnaces and factories have released.
This blue and green carbon pump stalled in 2023, the hottest year on record, amid heatwaves, droughts and fires. The possibility of nature’s carbon storage suddenly collapsing is not priced into the computer models that simulate and project the future climate.
However, the ecosystems that buffer human-made warming are clearly struggling. A new report from the World Wildlife Fund (WWF) showed that the average size of monitored populations of vertebrate wildlife (animals with spinal columns – mammals, birds, fish, reptiles and amphibians) has shrunk by 73% since 1970.
Wildlife could become so scarce that ecosystems like the Amazon rainforest degenerate, according to the report.
“More than 90% of tropical trees and shrubs depend on animals to disperse their seeds, for example,” says biodiversity scientist Alexander Lees (Manchester Metropolitan University).
“These ‘biodiversity services’ are crucial.”
The result could be less biodiverse and, importantly for the climate, less carbon-rich habitats.
Threats to wildlife are numerous. One that is growing fast and still poorly understood is plastic.
Bottles, bags, toothbrushes: a rising tide of plastic detritus is choking and snaring wild animals. These larger items eventually degrade into microplastics, tiny fragments which now suffuse the air, soil and water.
“In short, microplastics are widespread, accumulating in the remotest parts of our planet. There is evidence of their toxic effects at every level of biological organisation, from tiny insects at the bottom of the food chain to apex predators,” says Karen Raubenheimer, a senior lecturer in plastic pollution at the University of Wollongong.
Plastic is generally made from fossil fuels, the main agent of climate change. Activists and experts have seized on a similar demand to address both problems: turn off the taps.
In fact, the diagnosis of Costas Velis, an expert in ocean litter at the University of Leeds, sounds similar to what climate scientists say about unrestricted fossil fuel burning:
“Every year without production caps makes the necessary cut to plastic production in future steeper – and our need to use other measures to address the problem greater.”
A production cap hasn’t made it into the negotiating text for a plastic treaty (yet). And while governments pledged to transition away from coal, oil and gas last year, a new report on the world’s energy use shows fossil fuel use declining more slowly than in earlier forecasts – and much more slowly than would be necessary to halt warming at internationally agreed limits. The effort to protect a third of earth’s surface has barely begun.
Each summit is concerned with ameliorating the effects of modern societies on nature. Some experts argue for a more radical interpretation.
“Even if 30% of Earth was protected, how effectively would it halt biodiversity loss?” ask political ecologists Bram Büscher (Wageningen University) and Rosaleen Duffy (University of Sheffield).
“The proliferation of protected areas has happened at the same time as the extinction crisis has intensified. Perhaps, without these efforts, things could have been even worse for nature,” they say.
“But an equally valid argument would be that area-based conservation has blinded many to the causes of Earth’s diminishing biodiversity: an expanding economic system that squeezes ecosystems by turning ever more habitat into urban sprawl or farmland, polluting the air and water with ever more toxins and heating the atmosphere with ever more greenhouse gas.”
