Ten years after nearly every nation on the planet signed the historic Paris Agreement, a new United Nations report warns that the world is on track to officially breach the agreement's 1.5 degrees Celsius warming threshold within the next decade, triggering an escalation of climate change impacts worldwide.

On Tuesday, the UN Environment Programme published its annual Emissions Gap Report, warning that the average global temperature rise over multiple decades is likely to exceed the 1.5 degrees Celsius threshold within the next decade, at least temporarily.

The report finds that even the most ambitious emissions cuts would only delay the onset of the overshoot, not prevent it entirely and that by the end of the century, the world is projected to face a global average temperature rise of between 2.3 and 2.8 degrees Celsius above pre-industrial levels, depending on the pace and scale of mitigation efforts.

To stay on track for the Paris target, the report stated that global emissions would need to decrease by 40% by 2030 compared to 2019 levels. To accomplish this, the authors are urging countries to accelerate investment in renewable energy, expedite the phaseout of fossil fuels and increase financial support for developing nations that are most vulnerable to the impacts of climate change.

"While national climate plans have delivered some progress, it is nowhere near fast enough, which is why we still need unprecedented emissions cuts in an increasingly tight window, with an increasingly challenging geopolitical backdrop," said Inger Andersen, executive director of UNEP.

The report comes days before policymakers head to the annual UN Conference of Parties climate conference. This year, COP30 will take place in Belém, Brazil, the “gateway” to the Amazon rainforest, marking a decade since 195 countries adopted the Paris Agreement at COP21 in December 2015.

Delegates to COP30 are facing a world that, by many climate measures, is going in the wrong direction. Atmospheric carbon dioxide (CO2) emissions continue to climb, reaching record highs. In 2024, CO2 levels rose by 3.5 parts per million (ppm), the most significant annual increase since modern measurements began in 1957, according to the World Meteorological Organization.

"Proven solutions already exist. From the rapid growth in cheap renewable energy to tackling methane emissions, we know what needs to be done. Now is the time for countries to go all in and invest in their future with ambitious climate action," Andersen said.

-ABC News meteorologist Dan Peck

The United States' recent climate policy reversals come as record heat waves, rising pollution and billion-dollar weather disasters intensify. And according to the 2025 Lancet Countdown on Health and Climate Change report, these setbacks are contributing to the worsening of both national and global health.

Authored by 128 experts in medicine, public health and climate science, the report tracked 20 indicators linking climate trends to health outcomes. Twelve indicators reached record highs in 2024, underscoring what the authors call a "world in turmoil."

"As climate change intensifies, so do the health impacts it brings," Maria Walawender, a research fellow and the lead author for the Lancet Countdown, told ABC News. "We're seeing record-breaking threats to health--whether it's the suitability for the spread of dengue, the amount of our land experiencing drought, or the deaths related to heat exposure, which is now over half a million people a year."

In 2024, the U.S. experienced its warmest year on record, with average temperatures rising 2.7°F--the highest since pre-industrial times. Along with record scorching temperatures, heat-related deaths have also increased, spiking 63% globally since the 1990s and are associated with about 546,000 deaths a year, according to the report. The researchers found that roughly one-third of the country faced at least a month of extreme drought annually from 2020 to 2024, a 28% increase from the 1950s. Wildfire-risk days also hit record highs along the West Coast.

The old and young were hit hardest, according to the findings. Children under one year of age were nearly 400% more likely to experience a heatwave, and adults over 65 were nearly 390% more likely.

These climate shifts carry a steep economic cost too. The researchers found that weather-related disasters caused more than $27 billion in damages in 2024, while heat-related deaths cost $19.1 billion, approximately 0.35% of the national GDP.

"The overall theme of this report shows we're not going in the right direction," Yang Liu, another report author and the chair at the Rollins School of Public Health at Emory University, told ABC News. "There are more indicators showing negative signs than those showing positive signs. Which means, even though climate change is causing a lot of burden on health, we are not taking enough action to mitigate the impact."

Walawender added that U.S. policy rollbacks have made it harder to respond effectively.

"The United States has pulled out of the Paris Agreement. It has taken funding and support away from a lot of research on these types of issues and it's pulled out of the World Health Organization. And when taken together, that really kind of limits the financial support and the political pressure on climate-related action, but it also just limits how much we know about what's happening," she said.

Despite these setbacks, the report points to the U.S.'s potential. Clean energy growth accounted for 6% of GDP growth in 2023, and 16.2 million people now work in the clean energy sector worldwide, an 18% increase from 2022. The report urged the U.S. to restore global leadership by reinvesting in climate-resilient health systems and redirecting fossil fuel subsidies toward renewable power.

"There is so much that we can do, and that 'we' is quite inclusive," Walawender said. "We don't have to wait for a specific individual, no matter how important they are, or a specific institution to say, 'let's do it.'"

- Ogechi Nwodim, MD, MSc, is a resident physician in Emergency Medicine and a member of the ABC News Medical Unit

Atmospheric carbon dioxide (CO2) levels surged by a record amount last year, reaching new highs and locking in further long-term warming for the planet, according to a new report from the World Meteorological Organization (WMO).

From 2023 to 2024, the global average concentration of CO2 rose by 3.5 parts per million (ppm), the most significant annual increase since modern measurements began in 1957.

The WMO said ongoing human emissions, heightened wildfire activity and weakened absorption by land and ocean carbon sinks drove the increase. The WMO warned that the factors that could trigger a vicious cycle in which rising temperatures further impair the planet’s ability to absorb excess CO2, accelerating climate change.

Carbon sinks absorb more carbon dioxide than they emit, removing excess carbon dioxide from the atmosphere and providing a net reduction in the heat-trapping greenhouse gas.

Since the 1960s, the growth rate of atmospheric CO2 has tripled, accelerating from an annual average increase of 0.8 parts per million to 2.4 parts per million per year between 2011 and 2020, according to the analysis. Concentrations of two other long-lived greenhouse gases linked to human activities, methane and nitrous oxide, also reached new record highs last year. Last year was the warmest on record for the planet, driven by a strong El Niño event.

CO2 levels tend to rise during El Niño years as the climate pattern promotes persistently warmer, drier conditions in regions such as Canada, the Amazon and southern Africa, often fueling devastating wildfires. These wildfires, along with drier vegetation, reduce the efficiency of land-based carbon sinks, allowing more CO2 to remain in the atmosphere.

“There is concern that terrestrial and ocean CO2 sinks are becoming less effective, which will increase the amount of CO2 that stays in the atmosphere, thereby accelerating global warming,” said Oksana Tarasova, a WMO senior scientific officer. “Sustained and strengthened greenhouse gas monitoring is critical to understanding these loops.”

The Arctic tundra, once a long-standing carbon sink, has already experienced significant shifts. After serving as a vital carbon sink for thousands of years, the vast region has become a source of carbon dioxide emissions due to rapidly rising temperatures and increased wildfire activity, according to the National Oceanic and Atmospheric Administration (NOAA). The Arctic region is warming significantly faster than the global average.

While global air and sea surface temperatures are currently falling short of new record highs, climate scientists warn this pause is unlikely to persist as human-caused greenhouse gas emissions continue to drive the long-term warming trend.

A short-term decline in global temperatures was expected due to the La Niña event in the equatorial eastern Pacific Ocean, which ended in April. This climate pattern typically causes a temporary dip in average global temperatures. According to NOAA, La Niña conditions are now reemerging and are expected to persist into early 2026.

Because of its long lifetime in the atmosphere, present-day CO2 emissions not only impact global climate today but will continue to do so for hundreds of years, locking in intensifying effects for future generations.

-ABC News meteorologist Dan Peck

Fifty years ago, when a major hurricane threatened land, meteorologists had limited forecasting tools available. The satellite data technology was basic, consisting of low-resolution, black-and-white images that were infrequently updated. This made it far more difficult to pinpoint a storm’s strength and potential impacts.

Then came the National Oceanic and Atmospheric Administration’s (NOAA) Geostationary Operational Environmental Satellite (GOES) program. GOES, which celebrates its 50th anniversary this month, revolutionized weather forecasting by using state-of-the-art satellites that provide high-quality, real-time data that meteorologists use daily to monitor extreme weather. These satellites even serve as a backup to ground-based radar during outages, keeping forecasters informed when it matters most.

That redundancy proved critical in 2017 when Hurricane Maria knocked out radar in Puerto Rico just before making landfall. With this key data source offline, forecasters turned to newly available 30-second imagery from the GOES satellite to track the storm in real time, providing vital information during a life-threatening event.

"The greatest single advancement in observing tools for tropical meteorology was unquestionably the advent of the geosynchronous meteorological satellite," said Robert Sheets, the former director of NOAA's National Hurricane Center.

Geostationary satellites provide continuous, real-time observation of the same region on Earth. Because they orbit at the same rotational speed as the planet, they remain fixed over a single region, allowing meteorologists to monitor storm development, movement, and intensity with far greater precision.

Launched in 2016, the latest generation of GOES satellites, known as the GOES-R series, produces high-resolution rapid imaging and has the first lightning mapper flown in geostationary orbit. These satellites can monitor the entire Western Hemisphere, the U.S., and localized weather events simultaneously, with image updates ranging from every few minutes to as frequently as every 30 seconds, depending on the area and scope of observation.

That level of weather and climate insight wasn’t always possible. When NOAA launched its first geostationary satellite, GOES-1, on Oct. 16, 1975, it was a significant step forward, enabling day-and-night observations of cloud cover, surface temperatures, cloud heights, and wind patterns. However, it lacked the high-resolution, continuous data that today’s satellites provide, which are required for delivering the more accurate and detailed forecasts the public depends upon.

Operated by NOAA in partnership with NASA, the GOES program has evolved dramatically over the past five decades, reshaping how we observe Earth from space. Prior to NOAA’s formation in 1970, NASA led the development and launch of weather satellites, including the world’s first, TIROS-1, in 1960. On May 17, 1974, NASA launched SMS-1, the first operational satellite designed to observe meteorological conditions from geostationary orbit. Serving as a prototype for the GOES series, SMS-1 marked a turning point in satellite-based weather observation.

Over the last 50 years, the GOES program has tracked everything from major storms and destructive wildfires to volcanic ash clouds and solar activity. And it's become a critical tool for meteorologists, researchers and emergency managers as its high-quality, real-time data helps them make accurate weather observations and often life-saving decisions.

-ABC News meteorologist Dan Peck