Global Warming Accelerates: Sharp Increase Since 2015
New research shows the rate of temperature rise has doubled in the last decade.
1Clear Acceleration in Global Warming
A new analysis from the Potsdam Institute for Climate Impact Research (PIK) reveals that global warming has accelerated since around 2015. After removing natural temperature fluctuations, researchers found the first statistically significant evidence that the planet's long-term warming rate is increasing. Over the past decade, global temperatures have risen by approximately 0.35°C depending on the dataset, nearly double the 0.2°C average increase during 1970-2015.
2Consistency Across Datasets
Researchers analyzed five different global temperature datasets including NASA, NOAA, HadCRUT, Berkeley Earth and ERA5. All datasets showed over 98% statistical certainty of accelerated warming since 2015. US statistics expert Grant Foster stated, 'We filtered out natural influences in observational data, making the underlying long-term warming signal more visible.'
3Role of Natural Factors
Short-term temperature variations called 'noise' in climate data can temporarily mask or exaggerate underlying trends. For example, El Niño can temporarily raise global temperatures by releasing heat from the tropical Pacific Ocean. Volcanic eruptions can have the opposite effect by sending sunlight-reflecting particles into the atmosphere. Researchers isolated these temporary influences to reveal the fundamental trend.
4Two Statistical Approaches
The team used two statistical methods to determine if warming rates have changed since the 1970s. The first was quadratic trend analysis testing whether temperature curves bend upward over time. The second was a piecewise linear model dividing temperature records into periods to objectively identify rate changes. Both methods supported the conclusion that global warming has accelerated.
5Extreme Heat of 2023-2024
After adjusting for El Niño and solar maximum effects, the extreme warmth of 2023 and 2024 slightly decreased in analysis. Yet both years remained the hottest since instrumental records began in 1880. Acceleration became visible in all datasets starting in 2013-2014. Researchers describe the broader shift as beginning around 2015 when evidence became clearer.
6Alignment With Climate Models
The study was designed to detect and measure statistical acceleration, not determine exact causes. However, authors noted climate models can produce periods of accelerated warming. In other words, increasing warming rates fall within the range of behaviors represented in current climate modeling. These computer simulations use physics laws to estimate how Earth systems respond to greenhouse gases.
71.5°C Threshold at Risk
PIK researcher Stefan Rahmstorf warns, 'If the past decade's warming rate continues, it would lead to long-term exceedance of the Paris Agreement's 1.5°C limit before 2030.' The 1.5°C limit aims to restrict long-term global warming to 1.5°C above preindustrial levels. A single year above this threshold doesn't mean permanent crossing, as scientists focus on sustained warming over longer periods.
8Critical Role of Emissions
Findings suggest Earth may now be warming considerably faster than in late 20th century decades. Whether acceleration continues depends heavily on future CO2 emissions from coal, oil and gas. Rahmstorf adds, 'How fast Earth continues warming ultimately depends on how quickly we reduce global fossil fuel CO2 emissions to zero.'