Detectable anthropogenic climate change began considerably earlier than previously thought, according to new research from the international Past Global Changes 2000 year (PAGES 2K) Consortium.
The new work — which involved input from 25 different researchers from across Australia, the US, Europe and Asia — found that anthropogenic warming first started all the way back in the 1830s, right in the early stages of the Industrial Revolution.
It should probably be noted here that the new research mostly concerns warming associated with carbon emissions (industrial-age anthropogenic warming) — obviously, human-caused deforestation, desertification, etc., has had an enormous effect on the climate as well, but this is harder to trace back through the millennia.
Interestingly, the research found that the first warming detected (in the 1830s, as stated above) was in the Arctic, and in the tropical oceans.
The project’s lead researcher, Associate Professor Nerilie Abram, from The Australian National University (ANU) Research School of Earth Sciences and the ARC Centre of Excellence for Climate System Science, commented: “It was an extraordinary finding. It was one of those moments where science really surprised us. But the results were clear. The climate warming we are witnessing today started about 180 years ago.”
The researchers behind the work think that the new findings will help to improve the understanding of the relationship between greenhouse gas emissions and the climate.
Abram continued: “In the tropical oceans and the Arctic in particular, 180 years of warming has already caused the average climate to emerge above the range of variability that was normal in the centuries prior to the Industrial Revolution.”
The press release continues, noting that, according to Associate Professor Abram, anthropogenic climate change has generally been considered to be a 20th century phenomenon mostly just because earlier measurements of the climate are sparse.
The new work, though, utilized “detailed reconstructions of climate spanning the past 500 years to identify when the current sustained warming trend really began. Scientists examined natural records of climate variations across the world’s oceans and continents. These included climate histories preserved in corals, cave decorations, tree rings and ice cores. The research team also analysed thousands of years of climate model simulations, including experiments used for the latest report by the UN’s Intergovernmental Panel on Climate Change (IPCC), to determine what caused the early warming.”
Continuing: “The data and simulations pinpointed the early onset of warming to around the 1830s, and found the early warming was attributed to rising greenhouse gas levels. Associate Professor Abram said the earliest signs of greenhouse-induced warming developed during the 1830s in the Arctic and in tropical oceans, followed soon after by Europe, Asia, and North America. However, climate warming appears to have been delayed in the Antarctic, possibly due to the way ocean circulation is pushing warming waters to the North and away from the frozen continent.”
It’s worth noting here that the researchers also investigated the effects of major volcanic eruptions in the early 1800s on the climate, and found that they were only a “minor factor.”
One of the researchers, Dr Helen McGregor of the University of Wollongong’s School of Earth and Environmental Sciences, commented on the general nature of the release of “small quantities” of greenhouse gases during the 19th century: “The early onset of warming detected in this study indicates the Earth’s climate did respond in a rapid and measureable way to even the small increase in carbon emissions during the start of the Industrial Age.”
This article was perhaps a bit dry for the tastes of some, so it’s probably worth a reminder here … what’s in store for us as temperatures continue rising is essentially: the dismantling of current cultures, trade networks, nation-states, agricultural systems, deep-water seaport systems, and common identities.
As agricultural yields fall, as freshwater resources diminish in many regions, as accompanying civil and inter-state conflicts flare and trigger mass migrations, as disease vectors spread towards the poles … the foundational cause will often be anthropogenic climate change and its accompanying effects.
For an analog of what I expect to see occur over the coming centuries, I recommend a look back at the late-bronze-age collapse — a period of a few hundred years that saw the disappearance of a great many languages, alphabets, cultures, cities, technologies, trade networks, species, religions, etc. That was primarily through the actions of environmental destruction, agricultural problems, civil breakdown, (truly enormous) mass migrations, and typical primate behavior when in a prolonged state of stress.
Obviously, we’ll also be dealing this time with abandoned nuclear energy facilities and wastes, widespread chemicals and plastics pollution, overfished and acidified oceans, and greatly reduced genetic diversity amongst common crops.
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