Back to the past

As part of her doctoral dissertation at Stanford University, Carolyn Snyder, a climate official at the U.S. Environmental Protection Agency (EPA), conducted a study that predicts that the Earth will reach record-high temperatures in the next few thousand years, signifying the planet's hottest mark in more than 120,000 years.

In the study, Snyder created a 2-million-year record of temperature changes, much longer than the previous 22,000-year record. The years were lumped into 5,000-year time periods that go back a couple million years, with Snyder focusing on the average of each 5,000-year segment.

She examined how temperature change correlated with carbon dioxide levels. Her findings include the following:

  1. The average temperature in the most recent 5,000-year segment, which included the last 125 years of heat-trapping industrial emissions, was higher than any in the past 120,000 or so years.
  2. The Earth's warmest periods happened during two interglacial periods, around 120,000 years ago and about 2 million years ago, and those were about 2°C (3.6°F) warmer than the current 5,000-year period's average.

By following established trends from the past, Snyder predicted temperature changes in the future. If the same factors from the past affect the future, over the next few thousands years, the temperature of the Earth will increase about 4°C (7.2°F) compared to the average temperature of the current 5,000-year period.

"This is based on what happened in the past. In the past, it wasn't humans messing with the atmosphere," Snyder acknowledged.

Credits: NASA

The warmth of the future

Of course, the predictive nature of the study makes it inconclusive, and Snyder herself acknowledges that these are estimates prone to large margins of errors. Still, she believes that her conclusions hold, and whatever the specifics may be, it is clear that the Earth's temperatures are on a steady rise. Indeed, it is partly a course that nature takes, as evidenced by Snyder's study.

However, her study also showed how the trend has changed ever since humans started becoming capable of affecting global temperatures in the last 125 years. It's never too late, of course, to continue affecting it, but this time by mitigating the negative effects we have on the Earth's changing temperatures. It works both ways, really. We can continue to invest in solutions and means to improve the situation.


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