evidence: Since the Industrial Revolution began around 1750, human activities have contributed substantially to climate change by adding CO2 and other heat-trapping gases to the atmosphere. These greenhouse gas emissions have increased the greenhouse effect and caused Earth’s surface temperature to rise. The primary human activity affecting the amount and rate of climate change is greenhouse gas emissions from the burning of fossil fuels. [...] Carbon dioxide is the primary greenhouse gas that is contributing to recent climate change. CO2 is absorbed and emitted naturally as part of the carbon cycle, through plant and animal respiration, volcanic eruptions, and ocean-atmosphere exchange. Human activities, such as the burning of fossil fuels and changes in land use, release large amounts of CO2, causing concentrations in the atmosphere to rise. [...] Changes in solar energy continue to affect climate. However, over the last 11-year solar cycle, solar output has been lower than it has been since the mid-20th century, and therefore does not explain the recent warming of the earth.[2] Similarly, changes in the shape of Earth’s orbit as well as the tilt and position of Earth’s axis affect temperature on very long timescales (tens to hundreds of thousands of years), and therefore cannot explain the recent warming.