There's now more carbon dioxide in the atmosphere than there has been for millions of years, in part thanks to the CO2 humans have rapidly released in the last 100 years.

CO2 levels measured at the Mauna Loa Observatory in Hawaii on Tuesday topped 410 parts per million (ppm). We only hit 400 ppm in 2013, a steep increase in the last four years.

Read: CO2 And Climate Change: Human Activity Causes Global Warming

While the Earth does go through natural cycles of higher and lower levels of CO2 and periods of warming and cooling, the impact of human generated CO2 has led to the rapid warming that the planet is currently seeing. CO2 levels and temperature are directly correlated, meaning when CO2 levels increase so does temperature, according to the National Oceanic and Atmospheric Administration.

global temperature change This graph from the EPA shows the impact humans have had on global temperature change. Photo: EPA

So these record-breaking levels of CO2 mean the Earth is going to continue to warm at a rate not seen previously.

The warming planet poses a number of threats to life as we know it. Some of which include more variable weather,  increasing sea ice melt, rising sea levels and ocean waters with more CO2, also called ocean acidification, which can harm ecosystems and has an impact on coral reefs

The warming trend is continuing. March was the second warmest March on record, and CO2 levels are continuing to rise. All the while the United States is looking at the possible elimination of the Environmental Protection Agency and maybe exiting the Paris Agreement to lower carbon emissions.