We came across this post on Twitter:
The tweet, which has gone viral with 37 thousand likes at the time of writing alleges that NASA has admitted to climate change occurring because of changes in the Earth’s orbit, and not due to human activities as previously thought. The post also contains a link to an article by Signs of the Times (SOTT) news, which describes itself as a “leading alternative news site providing independent journalism and unbiased analysis”.
According to the article, the biggest factor affecting Earth’s climate is the sun, with the
article containing a link to a NASA publication from the year 2000 as purported proof that variations in shape and angles of the Earth’s orbit over thousands of years, as explained by the Milankovitch theory, alone explain the warming trends.
Simply put, Milankovitch theory describes three periodic variations in the way that Earth rotates around the sun. These changes to the geometry of Earth’s orbit strongly influence climate patterns as a result. In the claim then, these changes in the solar orbit of the Earth are the sole factors of climate change, and human activities have not been the main drivers of global warming.
However, NASA does not attribute climate change to the phenomenon. While Milankovitch (orbital) cycles do play key roles in Earth’s short-term weather and long-term climate, they do not explain Earth’s current warming. An article from NASA published shortly after the piece on Milankovitch theory explains that the orbital cycles cannot account for the current period of rapid warming Earth has experienced since the pre-Industrial period (the period between 1850 and 1900), and particularly since the mid-20th century, effectively debunking this claim.
As NASA explains, Milankovitch cycles are not to blame for global warming, as they operate on long time scales, ranging from tens of thousands to hundreds of thousands of years. In contrast, Earth’s current warming has taken place in scales of decades. The article concludes by describing the current state of Earth’s orbit as being in a cooling state if it was not for human activity induced global warming, stating that: “Earth is currently in an interglacial period (a period of milder climate between Ice Ages). If there were no human influences on climate, scientists say Earth’s current orbital positions within the Milankovitch cycles predict our planet should be cooling, not warming, continuing a long-term cooling trend that began 6,000 years ago”.
We also found that this claim had previously been making its rounds in cyberspace back in 2019, having already been debunked by Snopes and AFP in the past. Based on the official response by NASA and the factchecks that have previously rated this claim as false, it is false that NASA has admitted to climate change being due to the Earth’s orbit around the sun, not greenhouse gas emissions.
