"The first of the three Milankovitch Cycles is the Earth's eccentricity. Eccentricity is, simply, the shape of the Earth's orbit around the Sun. This constantly fluctuating, orbital shape ranges between more and less elliptical (0 to 5% ellipticity) on a cycle of about 100,000 years." source
"Axial tilt, the second of the three Milankovitch Cycles, is the inclination of the Earth's axis in relation to its plane of orbit around the Sun. Oscillations in the degree of Earth's axial tilt occur on a periodicity of 41,000 years from 21.5 to 24.5 degrees." source
"The third and final of the Milankovitch Cycles is Earth's precession. Precession is the Earth's slow wobble as it spins on axis. This wobbling of the Earth on its axis can be likened to a top running down, and beginning to wobble back and forth on its axis. The precession of Earth wobbles from pointing at Polaris (North Star) to pointing at the star Vega. When this shift to the axis pointing at Vega occurs, Vega would then be considered the North Star. This top-like wobble, or precession, has a periodicity of 23,000 years." source
The shortest of the Milankovitch Cycles is 23,000 years. We only have data going back to 1880, or 139 years ago. That said, how can you portend to have any clue what a normal rising and falling of temperatures is when you are missing 99.4% of the data? If there is any significant anthropogenic global warming, perhaps it's the only thing saving us from another ice age.
shortest cycle is the solar cycle of 11 years or so. plus it has a longer cycle and we are hitting rock bottom on that one by 2020 or so (grand miniimum). we do have longer data though from ice core drilling in greenland and antarctic and stuff.
also animals are not likely to adapt the change if it happens so quickly. we heading to mass extinction here if we increase temperature too fast. plus the more of the ice mets the faster the temperature actually increases. after 1.5 degrees increase we will find it impossible to reverse the change. also means more refugees since a lot of africa asia and south america will be inhospitable. starving because of less farmable land and more people in one place. climate change means also more disasters, more droughts and more floods.