The human climate niche are areas on Earth where humans have historically lived due to favorable climate conditions related to temperature and precipitation. For the past 6000 years, humans have mostly lived in the same climate conditions as they do now. In addition to humans, this climate niche is also where the production of crops and livestock typically takes place. The optimal mean annual temperature of this identified niche is around 52 °F to 59 °F (∼11 °C to 15 °C). But as the climate changes, the areas that fit within the human climate niche will change as well. This dataset identifies the current human climate niche, with land shaded to show which areas are more or less suitable for people, and then projects the future human climate niche in 2070 based on the climate projection scenario of RCP 8.5. Also included as an additional layer that can be turned on and off is a map that shows the areas where the mean annual temperature is greater than 84 °F (29 °C). Currently, only 0.8% of the global land surface has a mean annual temperature greater than 84 °F, but in 2070 that is projected to cover 19% of the global land and impact an estimated 3.5 billion people.
According to the researchers who developed this dataset, “The bottom line is that over the coming decades, the human climate niche is projected to move to higher latitudes in unprecedented ways. At the same time, populations are projected to expand predominantly at lower latitudes, amplifying the mismatch between the expected distribution of humans and the climate.” The researchers estimate that roughly 30% of the projected global population would have to move if people were to live in the human climate niche as they do now. They further suggest that “each degree of temperature rise above the current baseline roughly corresponds to one billion humans left outside the temperature niche, absent migration” for the socioeconomic SSP3 scenario.