Humans have impacted climate change. You don’t have to agree with Net Zero, you don’t have to like EVs, wind turbines, solar farms or heat pumps. You don’t even have to agree with the policies governments are introducing. But none of those things change the science. The IPCC’s Sixth Assessment Report looked specifically at human influence on the climate system. “It is unequivocal that human influence has warmed the atmosphere, ocean and land.” And when you actually read the report, the detail is pretty compelling. TEMPERATURE Global surface temperature in 2011–2020 was around 1.09°C warmer than 1850–1900. The IPCC estimates human-caused warming between 1850–1900 and 2010–2019 at 0.8°C–1.3°C, with a best estimate of 1.07°C. Natural factors such as changes in solar activity and volcanic eruptions… Their estimated contribution was between −0.1°C and +0.1°C. In other words, the estimated human contribution is roughly the same magnitude as the warming we’ve actually observed. GREENHOUSE GASES The IPCC states that the increases in major greenhouse-gas concentrations since around 1750 are unequivocally caused by human activities. By 2019 atmospheric concentrations had reached approximately: CO2: 410 ppm Methane: 1,866 ppb Nitrous oxide: 332 ppb Interestingly, greenhouse gases alone would likely have produced even MORE warming, estimated at 1°C-2°C. Other human effects, particularly aerosols, have actually offset some of that warming. THE OCEANS The upper ocean has warmed since the 1970s, and the IPCC says it is extremely likely that human influence is the main driver. Around 91% of the additional heat accumulating in the climate system has gone into the oceans. The IPCC also concludes that human CO2 emissions are the main driver of the current acidification of the surface open ocean. ICE Human influence is assessed as very likely the main driver of global glacier retreat since the 1990s. Arctic sea ice declined by around 40% in September between 1979–1988 and 2010–2019. Human influence is also assessed as very likely to have contributed to declining Northern Hemisphere spring snow cover. SEA LEVELS Global mean sea level rose by approximately 20cm between 1901 and 2018. More importantly, the rate accelerated: 1901–1971: 1.3mm/year 1971–2006: 1.9mm/year 2006–2018: 3.7mm/year The IPCC concludes that human influence was very likely the main driver since at least 1971. EXTREME WEATHER The report doesn’t say every individual heatwave, flood, drought or storm was “caused by climate change.” What it does say is that human-induced climate change is already affecting weather and climate extremes across every region of the globe. Hot extremes have become more frequent and intense across most land regions since the 1950s, with the IPCC concluding with high confidence that human-induced climate change is the main driver. Heavy precipitation events have also increased across most land areas where sufficient observations exist, with human-induced climate change assessed as likely the main driver. And marine heatwaves have approximately doubled in frequency since the 1980s. So no, this doesn’t mean Earth’s climate never changed naturally before industrialisation. Of course it did. The IPCC explicitly includes solar activity, volcanic activity and natural climate variability in its analysis. The important point is that those natural factors cannot explain the scale of the warming we’ve observed in the modern era. Human activity can. You can absolutely debate what we should do about climate change. That’s a political, economic and societal discussion worth having. But whether humans have affected the climate in the first place is a scientific question. And the evidence for that is now overwhelming. You don’t have to like climate policy to accept climate science. They’re two completely different conversations. Source: IPCC Sixth Assessment Report, Working Group I, The Physical Science Basis.