Yes, climate change is real.
Multiple independent lines of evidence show that Earth's climate is warming and that human activities are the dominant cause of the observed changes since the mid-20th century.
Key evidence
•Global temperature rise: Instrumental records show the planet's average surface temperature has increased by roughly 1.1–1.2°C (about 2°F) since the late 19th century, with the warmest years on record occurring in the most recent decades. This is confirmed by thermometer networks, satellite data, ocean heat content measurements, and paleoclimate proxies (ice cores, tree rings, sediments).
•Physical indicators:
•Shrinking glaciers and ice sheets (Greenland, Antarctica, mountain glaciers worldwide).
•Rising sea levels (thermal expansion of seawater + meltwater).
•Decreasing Arctic sea ice extent and snow cover in the Northern Hemisphere.
•Ocean acidification from absorbed CO₂.
•Shifts in seasons, earlier spring events, and changes in species ranges.
•Greenhouse gases: Atmospheric CO₂ has risen from ~280 ppm pre-industrially to over 420 ppm today, primarily from fossil fuel burning, deforestation, and cement production. Ice-core data show current levels are higher than at any point in at least the last 800,000 years. Methane and nitrous oxide have also increased. The radiative physics of these gases trapping heat is well-established laboratory and atmospheric science.
•Attribution: Climate models that include only natural factors (solar variability, volcanoes) cannot reproduce the observed warming; models that include anthropogenic greenhouse gases match the record. The fingerprint of human-caused warming appears in the troposphere/stratosphere temperature patterns, nighttime vs. daytime warming, and ocean heat uptake.
Scientific consensus
The Intergovernmental Panel on Climate Change (IPCC), NASA, NOAA, the World Meteorological Organization, and the national academies of science of every major industrialized country agree that warming is unequivocal and that human influence is the main driver. Reviews of the literature consistently find >97–99% agreement among actively publishing climate scientists on these points.
Natural climate variability (El Niño/La Niña, solar cycles, orbital changes, volcanic eruptions) exists and modulates the climate on various timescales, but it does not account for the long-term global energy imbalance and warming trend of the past 150+ years.
Climate change does not mean every location warms equally every year, nor that weather variability disappears. It means a shift in the baseline that increases the probability and intensity of heatwaves, heavy precipitation in some regions, droughts in others, and related impacts.
For primary data and summaries, see NASA’s climate site, NOAA’s Global Climate Report, or the IPCC Assessment Reports.