The IPCC finds that human activities have unequivocally warmed the climate - global average temperatures are roughly 1.1°C above pre-industrial levels and greenhouse gas concentrations are far higher. Future warming and sea level rise depend on emissions choices: low emissions can limit warming to near 1.0-1.8°C, while high emissions would produce substantially larger changes. Responses include rapid emissions reductions, adaptation, and everyday low-carbon choices.

The authority: IPCC and the science

The Intergovernmental Panel on Climate Change (IPCC) is the international scientific body that assesses climate science, impacts and response options. Its recent assessment reports present the consensus view on past change, current risks and future scenarios. The Paris Agreement (2015) now guides international action, replacing the Kyoto Protocol as the main post-2012 framework.

What we have already observed

  • Human activities have warmed the planet since the mid-1800s. The IPCC states this is unequivocal.
  • Atmospheric concentrations of long-lived greenhouse gases are far above pre-industrial levels. Carbon dioxide (CO2) rose from about 280 ppm before the industrial era to roughly 420 ppm in recent years .
  • Global average surface temperature has increased by about 1.1°C since pre-industrial times (approximately 1850-1900), with most of that rise occurring since the mid-20th century.
  • Warming shows across the climate system: rising sea surface temperatures, shrinking Arctic sea ice extent, melting glaciers and earlier snowmelt, and global mean sea level rise of roughly 20 cm over the 20th century.
  • The IPCC attributes the observed warming primarily to human-caused increases in greenhouse gases.

What models project for the future

  • Some additional warming is already committed because of past emissions 1. The size and timing of further warming depend strongly on how quickly emissions fall.
  • Depending on future emissions pathways, the IPCC projects a range of global warming by 2081-2100 relative to 1850-1900 from around 1.0°C (very low emissions) to upwards of about 4-5°C in high-emissions scenarios; specific scenario ranges are detailed in the IPCC AR6 report.
  • Global mean sea level is projected to rise further this century. The IPCC gives scenario-dependent estimates that span several tenths of a meter to around a meter by 2100, with larger contributions possible from ice-sheet instability in Antarctica.
  • Continued CO2 uptake by the oceans will lower surface ocean pH, making waters more acidic and increasing stress on marine ecosystems and shell-forming organisms.

What this means and what you can do

The science indicates ongoing and growing risks from climate change if emissions remain high. Many responses reduce risk: cut fossil fuel use, improve energy efficiency, electrify transport, shift to low-carbon diets, reduce waste, and support strong policies that accelerate emissions reductions and fund adaptation.

Small actions matter and scale with policy and technology: household efficiency and low-carbon choices reduce emissions now; public support for systemic change (clean energy investment, urban planning, resilient infrastructure) multiplies impact.

  1. Confirm the latest atmospheric CO2 concentration (ppm) for 2024-2025 from Mauna Loa or NOAA and update the article figure if needed.
  2. Verify the best current estimate of 'committed warming' due to past emissions and update the text if more precise values are available for 2025.

FAQs about Environmental Facts

What is the IPCC?
The IPCC (Intergovernmental Panel on Climate Change) is the UN body that assesses and synthesizes peer-reviewed climate science to inform governments and the public.
How much has the world warmed so far?
Global average surface temperature has increased by about 1.1°C since pre-industrial times (about 1850-1900), with most warming since the mid-20th century.
Are humans causing the warming?
Yes. The IPCC concludes that the observed warming is primarily the result of human-caused increases in greenhouse gases.
How high could global temperatures rise?
Projected warming by 2081-2100 depends on emissions. Low-emission pathways keep warming close to 1.0-1.8°C, while high-emission pathways could lead to several degrees Celsius of additional warming.
What can individuals do to help?
Individuals can reduce emissions by improving home energy efficiency, using low-carbon transport, choosing lower-emission diets, reducing waste, and supporting policies that accelerate the clean-energy transition.