You don't have to look far to see what climate change is doing to the planet. The word "unprecedented" is everywhere this year.
Authors
Thomas Newsome
Associate Professor in Global Ecology, University of Sydney
William Ripple
Distinguished Professor and Director, Trophic Cascades Program, Oregon State University
We are seeing unprecedented rapidly intensifying tropical storms such as Hurricane Helene in the eastern United States and Super Typhoon Yagi in Vietnam. Unprecedented fires in Canada have destroyed towns. Unprecedented drought in Brazil has dried out enormous rivers and left swathes of empty river beds. At least 1,300 pilgrims died during this year's Hajj in Mecca as temperatures passed 50°C.
Unfortunately, we are headed for far worse. The new 2024 State of the Climate report, produced by our team of international scientists, is yet another stark warning about the intensifying climate crisis. Even if governments meet their emissions goals, the world may hit 2.7°C of warming - nearly double the Paris Agreement goal of holding climate change to 1.5°C. Each year, we track 35 of the Earth's vital signs, from sea ice extent to forests. This year, 25 are now at record levels, all trending in the wrong directions.
Humans are not used to these conditions. Human civilisation emerged over the last 10,000 years under benign conditions - not too hot, not too cold. But this liveable climate is now at risk. In your grandchild's lifetime, climatic conditions will be more threatening than anything our prehistoric relatives would have faced.
Our report shows a continued rise in fossil fuel emissions, which remain at an all-time high. Despite years of warnings from scientists, fossil fuel consumption has actually increased, pushing the planet toward dangerous levels of warming. While wind and solar have grown rapidly, fossil fuel use is 14 times greater.
This year is also tracking for the hottest year on record, with global daily mean temperatures at record levels for nearly half of 2023 and much of 2024.
Next month, world leaders and diplomats will gather in Azerbaijan for the annual United Nations climate talks, COP 29. Leaders will have to redouble their efforts. Without much stronger policies, climate change will keep worsening, bringing with it more frequent and more extreme weather.
Bad news after bad news
We have still not solved the central problem: the routine burning of fossil fuels. Atmospheric concentrations of greenhouse gases - particularly methane and carbon dioxide - are still rising. Last September, carbon dioxide levels in the atmosphere hit 418 parts per million (ppm). This September, they crossed 422 ppm. Methane, a highly potent greenhouse gas, has been increasing at an alarming rate despite global pledges to tackle it.
Compounding the problem is the recent decline in atmospheric aerosols from efforts to cut pollution. These small particles suspended in the air come from both natural and human processes, and have helped cool the planet. Without this cooling effect, the pace of global warming may accelerate. We don't know for sure because aerosol properties are not yet measured well enough.
Other environmental issues are now feeding into climate change. Deforestation in critical areas such as the Amazon is reducing the planet's capacity to absorb carbon naturally, driving additional warming. This creates a feedback loop, where warming causes trees to die which in turn amplifies global temperatures.
Loss of sea ice is another. As sea ice melts or fails to form, dark seawater is exposed. Ice reflects sunlight but seawater absorbs it. Scaled up, this changes the Earth's albedo (how reflective the surface is) and accelerates warming further.
In coming decades, sea level rise will pose a growing threat to coastal communities, putting millions of people at risk of displacement.
Accelerate the solutions
Our report stresses the need for an immediate and comprehensive end to the routine use of fossil fuels.
It calls for a global carbon price, set high enough to drive down emissions, particularly from high-emitting wealthy countries.
Introducing effective policies to slash methane emissions is crucial, given methane's high potency but short atmospheric lifetime. Rapidly cutting methane could slow the rate of warming in the short term.
Natural climate solutions such as reforestation and soil restoration should be rolled out to increase how much carbon is stored in wood and soil. These efforts must be accompanied by protective measures in wildfire and drought prone areas. There's no point planting forests if they will burn.
Governments should introduce stricter land-use policies to slow down rates of land clearing and increase investment in forest management to cut the risk of large, devastating fires and encourage sustainable land use.
We cannot overlook climate justice. Less wealthy nations contribute least to global emissions but are often the worst affected by climate disasters.
Wealthier nations must provide financial and technical support to help these countries adapt to climate change while cutting emissions. This could include investing in renewable energy, improving infrastructure and funding disaster preparedness programs.
Internationally, our report urges stronger commitments from world leaders. Current global policies are insufficient to limit warming to 1.5°C above pre-industrial levels.
Without drastic changes, the world is on track for approximately 2.7°C of warming this century. To avoid catastrophic tipping points, nations must strengthen their climate pledges, reduce dependence on fossil fuels, and accelerate the transition to renewable energy.
Immediate, transformative policy changes are now necessary if we are to avoid the worst effects of climate change.
Climate change is already here. But it could get much, much worse. By slashing emissions, boosting natural climate solutions and working towards climate justice, the global community can still fend off the worst version of our future.
Thomas Newsome receives funding from the Australian Research Council. He is immediate past-president of the Australasian Wildlife Management Society and President of the Royal Zoological Society of New South Wales.
William Ripple receives funding from the CO2 Foundation and University of Oregon donor Roger Worthington.
