2023 is the hottest year in at least 174 years and recent months have been the hottest in 125,000 years. All of that warming led to deadly heat waves, disease outbreaks, floods, droughts, and record low ice levels around Antarctica.

The extreme weather this year stems in part from natural variability, including a powerful El Niño warming pattern in the Pacific Ocean that reshaped weather around the world. But beneath these cycles, humanity’s ravenous appetite for coal, oil, and natural gas is driving up concentrations of heat-trapping gasses in the atmosphere to levels the Earth hasn’t witnessed for 3 million years.

This year may be the first time that annual temperatures have risen 1.5 degrees Celsius, 2.7 degrees Fahrenheit, above the global average at the dawn of the industrial revolution. Under the 2015 Paris agreement, just about every country in the world agreed to keep the planet’s average temperature from rising more than 2°C, striving to stay below 1.5°C. A single year rising past this level doesn’t mean this target is toast, but if people keep heating up the planet, a year like 2023 will become one of the coolest we’ll experience in the rest of our lives.

Earlier this month, leaders from around the world just wrapped the largest climate conference in history aimed at preventing this outcome. The COP28 meeting in the United Arab Emirates produced an agreement that explicitly called on countries to reduce fossil fuel use for the first time and provide more money to countries facing destruction worsened by warming. But the commitments made so far are still not enough to limit warming to 1.5°C, and greenhouse gas emissions continue to rise.

Half a world away, scientists who study this warming and its consequences gathered at the American Geophysical Union conference in San Francisco. Climate change is not an abstraction for these researchers, and many are observing it in real time, often in areas that have personal stakes for them. Looking back on the hottest year on record and what little humanity has done about it, some are reckoning with how their own work fits in. From the retreat of Arctic ice to rising demand for air conditioning, scientists with their fingers on the pulse of the planet are experiencing a mix of optimism, dread, and urgency as they endeavor to make their research practical in the real world.

Umair Irfan/Vox

I spoke with seven researchers studying Earth’s changes from different angles. Their comments below have been lightly edited.

Daniel Schindler at the University of Washington researches how climate change affects aquatic ecosystems, including Alaska’s sockeye, chinook, and chum salmon. He was one of several scientists presenting the National Oceanic and Atmospheric Administration’s Arctic Report Card for 2023 at the conference. The Arctic has been warming four times faster than the rest of the planet, and this year, the region saw its warmest summer since 1900 (when record-keeping began), with knock-on effects like Canada’s worst wildfire season on record. As negotiators in the United Arab Emirates bickered over the future of the planet, Schindler noted that the effects of climate change are underway now, and it’s already reshaping ecosystems and human communities:

I think the reality is, if you look at Western Alaska, climate change is not something that’s coming down the pipe somewhere in the future. It is happening now, it’s been happening for decades. And whether you’re talking about fish or people or birds, there are real impacts that we need to deal with right now.

And when you hear about what’s going on at COP28, there may be a reason to be optimistic. But the reality is, we need action on the ground right now, not to necessarily turn around climate change immediately, but to deal with the fact that we’re going to be challenged by it, now and for decades to come, so we need action now at local scales.

Rick Thoman, who studies Alaska’s climate and weather at the University of Alaska Fairbanks, echoed the call for more immediate steps to deal with global warming, noting that the Arctic has been at the leading edge of climate change long before it reached the extremes seen this year. The communities there may have important lessons for the rest of the world:

As Alaskans, as peoples in the Arctic, we are living this change every day. And we have no choice, no choice at all, other than to work with what’s happening. We need the big picture solutions, but everyone — Indigenous communities, all the people of the Arctic — are having to adapt right here, right now. It didn’t start today. It didn’t start yesterday. This has been ongoing for years. Listen to the elders. This change has been happening for decades, century-scale changes. And Arctic peoples are still here and we’re still going to be here.

Sarah Cooley, an assistant professor at the University of Oregon, is studying how climate change is altering ice in places like coastal Alaska and has found that when you zoom in, the way it affects people can be quite complicated. How ice melts and the impacts it has on communities can vary drastically, even in nearby regions. With COP28 still falling short of global climate goals, Cooley is also looking into the way the success or failure of international negotiations will manifest on the ground:

In this broader context of warming climate, loss of ice, thawing permafrost, threats of coastal erosion, and sea level rise, that’s kind of this giant signal that each person experiences differently depending on their interaction with their environment.

I get really excited about being able to do research that is locally relevant. One of the things we did in this project is we’re thinking about how Paris climate agreement targets translate to local on-the-ground experiences. If you tell somebody that the Earth is going to warm by 1.5°C or 2°C, that’s an incredibly abstract concept because the difference to us of two degrees doesn’t mean anything. But if you can translate that experience of two degrees warming to an actual on-the-ground experience that’s highly localized — so let’s say a loss of 30 days of ice versus 50 days of ice, which is a huge deal for someone living in the community to lose a month of ice versus losing two months of ice — that to me is really exciting work that we can kind of take large-scale big numbers that are really abstract and bring them down to a local experience.

Robert Green, a scientist at NASA’s Jet Propulsion Laboratory, is leading a project to track mineral dust using instruments on the International Space Station. This is an important mechanism that can change air quality, the flow of nutrients across the planet, and the amount of sunlight hitting the Earth, which can cool the planet. Green is also keeping an eye on methane, a greenhouse gas with about 30 times the warming potential of carbon dioxide. At COP28, countries made new pledges to curb methane, and Green said scientists can help them meet their targets:

We can tell people where the point sources of methane are, where leaks are happening, and give people the information to address those leaks. And that’s something that is just so important to do. Nobody wants to waste money out of a leaking pipeline. Let’s go ahead and fix those leaks, and we also reduce the impact of methane for climate change.

I’m excited to be making a difference. I’m an optimistic person, and we can work together to address this problem. It’s not an easy problem, but the pieces are coming together. So I’m going to remain hopeful.

Umair Irfan/Vox

Stepp Mayes, a doctoral student at the University of Southern California, studies how people use electricity and the ensuing consequences for the climate and for health. Lately he’s been examining the growing demand for air conditioning as temperatures rise and the stresses that imparts on the power grid. As temperatures go up, people install more cooling systems, run them longer, and crank them up during the hottest times of day. That’s often when the power grid is struggling the most to provide electricity. The extreme heat this year coupled with record-high energy demand signals that this work is only going to become more important:

It makes me nervous. There’s a big intersection because we’re all about looking at the relationship between temperature and AC use and AC penetration. I think that people are directly responding to increasing temperature, and I think we are going to see that continue as temperatures continue to rise, where our reliance on AC — as a public health issue, and as a grid issue — becomes larger and larger.

Aliyah Griffith, a doctoral student at the University of North Carolina Chapel Hill, studies coral reef infrastructure around places like Barbados, from satellites and from the water. Griffith is also the founder and CEO of Mahogany Mermaids, a nonprofit that works to encourage women of color to pursue careers in science, particularly in aquatic fields. The extreme temperatures this year, including heat waves in the ocean, have renewed her determination:

My family is from Barbados. Not only does that make me feel more driven to answer questions from a scientist’s perspective — how can we help the reefs? How can we understand what they need and what they’re facing? — but also: What do the communities need? How can we interact with their local governments, their local institutions, and understand where they can be elevated? You have to really respect a lot of the work and effort that they’ve already done to see what can change in the future.

Gordon Walker, a researcher at the University of Hawai‘i at Manoa, studies paleoclimate, particularly how past shifts in the climate and weather influenced historical events. For instance, changing climate conditions in Africa and the Caribbean were a factor in the slave trade and may have played a part in uprisings. For Walker, the role of the climate in historical periods of unrest is adding urgency for the need to fill in data gaps as the climate breaches records, particularly in regions experiencing the most acute impacts of warming today:

For me — my focus being the Caribbean and Africa, and the transatlantic slave trade, and climate variability associated with those regions and the historical event of the trade — I think that it’s important for us to collect data on regions in the global South — the Caribbean, South America, Africa — because a lot of the science and research is focused on the global North.

I think it’s imperative, especially in areas where we don’t have a lot of data, to start collecting data and applying the powers or the tools of analysis that we have for climate to the global South. Because a lot of countries in those regions are not necessarily resource-poor in terms of raw material but resource-poor in terms of economies and having the ability to respond to extreme climate. So I think the greater lead time we have with projections based on studying the past, the better for those countries to be able to respond, especially with limited economies, as compared to countries in the global North.