The historical temperature change was the Medieval Warming Period. The Medieval Warming Period, also known as the Medieval Optimal Climate, was a period of warm climate in the North Atlantic region during the Middle Ages. The causes (probably) of the MWP were increased solar activity, decreased volcanic activity, and changes in ocean circulation. The medieval warming period was followed by a cooler period in the North Atlantic; called the Little Ice Age. Possible causes of the Little Ice Age were cyclic lows of solar radiation, intensification of volcanic activity, changes in ocean circulation, changes in Earth's orbit and axial tilt (orbital forcing), intrinsic climate variability global and the decline of the human population. no to plagiarism. Get a tailor-made essay on "Why Violent Video Games Shouldn't Be Banned"? Get an original essay Global temperature, carbon dioxide and methane levels have also changed over time. Thermometer readings around the world have increased steadily since the start of the Industrial Revolution. According to an ongoing temperature analysis conducted by scientists at NASA's Goddard Institute for Space Studies (GISS), the global average temperature on Earth has increased by about 0.8° Celsius (1.4° Fahrenheit) since 1880. The levels of carbon dioxide have changed significantly over time as WELL; during ice ages, CO2 levels were around 200 parts per million (ppm), and during warmer interglacial periods they hovered around 280 ppm (see fluctuations in graph). In 2013, CO2 levels exceeded 400 ppm for the first time in history. This recent unstoppable increase in CO2 shows a remarkably consistent relationship with fossil fuel consumption and can be well explained based on the simple premise that approximately 60% of fossil fuel emissions remain in the air. Methane levels have also recently increased. In 1985 the average concentration was 1,620 parts per billion (ppb). By 2015 it had increased to 1,800 ppb. (Before the Industrial Revolution, concentrations held steady at about 700 ppb.) But the rate of increase has varied in recent decades. From the 1980s through 1992, methane increased about 12 ppb per year. Then came about a decade of slower growth of 3 ppb per year. Starting in 2007, they began to increase again and have continued to do so ever since, increasing at a rate of 6 ppb per year. There are other consequences that are occurring right now due to global warming, such as bleaching of coral reefs, increased droughts, longer and stronger hurricanes, rising sea levels, rising temperatures of the ocean and ocean acidification. Each of these consequences is mainly due to climate and temperature changes resulting from global warming. Humans have had, and continue to have, an enormous impact on the atmosphere. The Industrial Revolution, while greatly advancing our technology and our development as a society, was what began to create major problems with the Earth's atmosphere. The largest effect humans have on the atmosphere is the production of greenhouse gases, which trap heat in the atmosphere. Heat trapped in the atmosphere causes global temperatures to rise, which in turn also affects the climate. Global temperature, as previously stated, is rising. When the Earth emerged from the ice age, global temperatures increased by 4 to 7 degrees Celsius overall in about 5,000 years. Only in the last century,..