Fears of Gulf Stream Collapse Fade as Hard Data Reveal Major Role of Natural Variation

In July 2023, Georgina Rannard of the BBC ran a ‘scientists say’ story stating that the Gulf Stream system of warm ocean currents “could collapse as early as 2025”. It would be difficult to find a more tosh-filled tale of climate bunkum so perfectly constructed to fill the population with alarm and a willingness to accept the collectivist Net Zero fantasy. All the recent evidence, other than the findings of rigged computer models, is providing conclusive proof that the Gulf Stream is currently stable, although subject to higher-than-expected natural variations in what are often very short time intervals.

For 20 years the RAPID-MOCHA-WBTS Array has measured the movements along the Atlantic Ocean at 26°N. A number of submerged stations have collected large amounts of data on the currents that bring warm waters from the Gulf up to the Arctic and return them cooled, heavier and saltier back to the south. Alarmists and Net Zero fantasists have long argued that humans interfere with this process. In unison they wail (perhaps next year!) that a ‘tipping point’ could be reached where the currents reverse and bring ice age weather to countries in the northern hemisphere.

But findings from computer models that have produced countless The Day After Tomorrow headlines are being rendered increasingly worthless by the actual RAPID data. In fact, there has been a largely unannounced pause in any weakening of the Gulf Stream – also known as the Atlantic Meridional Overturning Circulation (AMOC) – since the early 2010s. Before that, and going right back to the start of measurements in 2004, the strength was generally relatively high, but there was a substantial weakening between 2009-2010. Such was the scale of this temporary weakening that the 20-year record has been skewed to show a 6% decadal decline. But RAPID has shown that sharp changes on a daily to inter-decadal period are the norm rather than exceptional. All of this is likely to be due to natural variation – what is often referred to as ‘noise’ – rather than any human cause.

Many of the fluctuations appear to be driven by changing air currents rather than deeper water formulations alone. These findings are starting to fundamentally change the way scientists understand the operation of the AMOC and mean that single or short-period snapshots are inadequate in measuring long-term strength. Needless to say, computer models are simply not up to the task of separating out any noise arising from the natural variability.

The scale of the natural variation can be truly astonishing. The RAPID observations from 2004-25 show a weakening of 1 Sv per decade in the AMOC. This is oceanographic-speak for a volume of water transported per second – 1 Sverdrup (Sv) equals one million cubic metres of water. The AMOC has an average strength of around 16-18 Sv, so the 20-year 6% average decadal decline is measurable but not necessarily significant given the enormous outlier recoded around 2010. In fact, RAPID has found that the AMOC can vary by several Sverdrups over months to years. The decline in 2009-2010 saw a 30% weakening which, since that time, has been restored. Some idea of the enormous changes discovered can be seen by comparing the 2009 Sv figure of 14.6 with the 18 Sv flowing in 2018. The one cause behind this huge change we can confidently rule out is humans using hydrocarbons.

The latest RAPID data show strong years in both 2023 and 2024, with flows around 17-18 Sv. Both these years have witnessed some of the highest flows recorded over the last two decades.

As with much climate science, a 20-year period of observation is a useful start but a clearer picture accounting for natural variation only emerges in a much longer time frame. The same principle applies to temperature measurement. In the world of climate Armageddon hype, the periods used to suggest long-term global warming seem to get smaller by the day. In the UK, it is by the day, hence the constant panic generation whenever the summer temperature rises above 30°C. This of course is why the scientific process has been largely trashed over climate. Debate is unwelcome, often penalised, since the matter is ‘settled’. Implausible proof is claimed from computer models running all manner of pseudoscientific attribution tales of bedwetting doom.

But away from clickbait Gulf Stream hysteria, some scientists are using RAPID’s growing volume of valuable data to increase understanding of the AMOC. In 2024, Dr Sang-Ki Lee, a Miami-based oceanographer working for NOAA, led a paper that observed a pause in any AMOC weakening since 2010, despite the growth of computer models projecting catastrophic anthropogenic decline. Despite these common modelled declines, Lee et al. notes that observations show “remarkable resilience” for the AMOC. Within any reasonable margin of error, it was found that the strength of the AMOC has been stable since around 2010. Looking forward, the authors suggest natural variation will keep the trend stable for several years to come.

There has been a pull back on the collapsing Gulf Stream scare of late. Computer model findings still broadcast plenty of human involvement, but genuine scares only have real legs when they are based on actual scientific observations and facts. The models assume that melting sea ice in the Arctic caused by humans burning hydrocarbons will freshen the water and interrupt the overturning flow to deeper waters. In a recent article published in Science, Susan Lozier, an oceanographer at Georgia Institute for Technology, observed: “That paradigm isn’t holding up.”

The Lee et al. paper refers to an underlying anthropogenic weakening produced by modelled suggestions. But RAPID provides actual proof that natural variation is far more important in determining how the Gulf Stream behaves. Another Net Zero scare bites the dust.

Chris Morrison is the Daily Sceptic’s Environment Editor. Follow him on X.