The period began roughly 130,000 years ago and ran until about 115,000 years ago, bringing temperatures that were 1-2 degrees Celsius (1.8 to 3.6 degrees Fahrenheit) warmer than what we have today. That may not sound like much, but it was enough to melt ice sheets and glaciers around the planet, bring sea levels 20 to 30 feet higher than their current levels.
The Eemian Period was part of a natural warming and cooling cycle of the planet, which has occurred on a regular basis, with gradual changes in temperature stretching out over hundreds of thousands of years. Researchers have been aware of those changes for a very long time and have even been able to explain them as part of the Earth's cycle. That isn't the case with our current warming period, which has essentially occurred over the past 150 years –– a very short time in geological terms.
The warming that we've seen over the past few years, which have brought us the hottest months recorded since meteorologist first began keeping readings back in 1880, has likely put the Earth above the Holocene Period, which occurred following a mini-ice age about 7000 years ago. That means that we're now at our warmest point since the Eemian, which as we know had a direct impact on the planet, even altering maps and coastlines significantly.
The main difference between now and the Eemian Period is the amount of carbon dioxide that is in the air. Scientists say that the Earth has reached a point were more CO2 is in the atmosphere than we've seen in 800,000 years. During the Eemian, the amount of greenhouse gases in the air was about 280 parts per million. Currently, it sits at 409 ppm.
What does this all mean for the future of our planet? That's tough to say, but it certainly isn't going to be great for us humans. At this rate, we'll begin to see rising ocean levels sooner than expected and we've already experienced changes to weather patterns as well. It is getting to the point where it doesn't matter whether or not climate change is man-made or not, it seems to be here and its going to have a significant impact on our lives and for the generations that follow us.