Once upon a time, about 3 million years ago, a genius emerged that would change everything, everything. The planet would never be the same again. The genius was Homo,Our genus. At about the same time, when our genius emerged, the climate on earth was changing drastically. There is growing evidence that some critical evolutionary steps coincide with times of significant climate change. For instance, about three million years ago, Africa changed from being covered by wooded areas to open grasslands. The direct change may have led early humans to give up climbing and learn to walk upright. Changing climate Climate proxy records Display that natural fluctuations balanced the early impact of the Industrial Revolution, so little net warming occurred between the 18th and mid-19th centuries, As records of thermometers started having a global scope. The Intergovernmental Panel on Climate Change (IPCC) introduced the baseline reference duration 1850–1900 as an estimate of global mean surface temperature for pre-industrial use. Various experimental datasets developed independently indicate that the decade 2009–2018 was 0.93 ± 0.07 ° C warmer than the pre-industrial baseline (1850–1900). The surface temperatures actually increase by about 0.2 ° C per decade.
The number of cold days and nights has declined since 1950, and the number of warm days and nights has increased. Historical warming and cooling cycles, such as the Medieval Climate Phenomenon and the Little Ice Age, were not as synchronous as current warming, but may have exceeded temperatures as high has those of current warming Nevertheless, in a small number of areas, temperatures could have reached as high as those of the late 20th century. The observed temperature increase and concentrations of CO 2 have been so rapid that even sudden geophysical events will not exceed the current levels. While the most common indicator of global warming is the rise in atmospheric near-, over 90 percent of the extra energy in the climate system has been deposited in the ocean over the last 50 years, warming it up. The majority of the surplus energy has melted ice and warmed up the continents and the atmosphere. The warming evident in the instrumental temperature record is consistent with a wide variety of findings, recorded by many independent research groups; for example, the frequency and intensity of heavy precipitation has risen in most continental regions.
Other examples include the rise in sea level, widespread snow and land ice melting, increased ocean heat production, increased humidity, and the earlier timing of spring events, such as the flowering of plants. Climate change feedback The climate system\'s response to initial forcing is strengthened by self-reinforcing feedback, and reduced by balancing feedback. The key mitigating input to global climate change is radiative space cooling as an infrared light, which increases rapidly as temperature rises. The key feedbacks are the feedback from water vapour, the feedback from ice – albedo, And perhaps the net impact of clouds. Uncertainty about feedback is the key reason why various climate models are predicting various magnitudes of heating for a given pollution level. It will retain more humidity as air gets warmer. Following an initial warming due to greenhouse gas emissions, more water will remain in the atmosphere. This further heats the atmosphere because water is a strong greenhouse gas: water vapor feedback. Decreasing snow cover and sea ice in the Arctic decreases the Earth\'s surface albedo.
Across these areas, much of the Sun\'s energy is now consumed, leading to Arctic amplification, which has caused Arctic temperatures to rise at more than twice the pace of the rest of the planet. Arctic amplification also allows methane to be emitted when permafrost melts, and is predicted to overtake shifts in land use by the end of the century as the second largest anthropogenic source of greenhouse gases. In the future, cloud cover will change. As cloud cover decreases, it reflects more sunlight back into space, cooling the earth. Around the same time, clouds are raising the greenhouse effect, warming the earth. When cloud cover reduces the reverse is true. Which process is more important depends on the type of cloud and the location. Overall, there\'s possibly net input over the industrial era as probably been self-reinforcing.
Plants on land and in oceans have absorbed nearly half of the CO2 emissions per year. Carbon dioxide and an extended growing season have stimulated plant production, resulting in a balancing input on the land carbon cycle. Climate change also increases droughts and heat waves which inhibit plant growth, making it uncertain whether this balancing feedback will continue in the future. Soils are rich in carbon and can release some as they heat up. Because the ocean consumes more CO2 and heat, it is acidifying and the composition of the ocean can change, increasing the rate at which the ocean can consume the atmospheric carbon. Self-reinforcing temperature feedback can lead to a tipping point where the Earth is turning into a hothouse atmosphere, even when greenhouse gas emissions are reduced or eliminated.Dare to be the change.