Laws noted another, rather frightening scenario: the Atlantic Meridional Overturning (AMOC) is an ocean current system that distributes warm water from the southern tip of the Earth to the north. This has a major impact on the weather in North America and Europe, keeping these regions much warmer and wetter than they would be otherwise. The problem is that as the Earth’s climate changes, the AMOC could break down in just a few decades. Several studies have recently explored this possibility. Including those published last yearThe analysis suggests that AMOC collapse could begin as early as 2025, but it also suggests that it may not actually begin until the end of the century.
In such a scenario, the average temperature across Europe would be It can drop to as low as 8 degrees. A 2022 analysis from the Organization for Economic Cooperation and Development (OECD) projects that North America could see temperatures rise by up to 3 degrees Celsius. That may not seem like much, but it could mean the coldest days get even colder.
“That would have a pretty big impact,” Laws stresses. “It would have an impact.” That means that some heat-pump installations designed for a minimum outside temperature of minus 10 degrees Celsius, for example, might no longer be enough. “You might need to think about bigger heat pumps,” Laws says. But if the AMOC really did break down, he adds, a country like the UK, where extreme cold is rare, would face bigger problems. Underground pipes freezing and snowstorms making roads impassable would be bigger problems.
AMOC collapse aside, it’s worth noting that winters are expected to get warmer in general due to climate change, but the coldest days in places like California will likely remain just as cold, says Duncan Callaway, professor of energy and resources at the University of California, Berkeley. “The heatwaves will be even more challenging,” he argues, highlighting the increased demand for cooling technologies. Air-to-air heat pumps differ from many competing technologies in that they can provide both heating and cooling.
While it’s difficult to predict exactly what shape climate change will take in the next few years, the broad trends are pretty clear, including expectations of greater variability and extreme weather. As power grids begin to rely more and more on renewable energy sources like solar and wind, this could have indirect effects on heat pumps.
For example, short periods of favorable weather can create surplus energy on the grid more frequently. Grid operators need to balance energy production and consumption to avoid blackouts, and heat pumps could actually be a useful tool here, says Joanna Mathews, an associate professor of electrical engineering and computer science at the University of Michigan. “If we had more heat pumps, we could do that job better,” she says, explaining that heat pumps could in principle be controlled remotely to use slightly more energy than usual, helping to balance the grid. Mathews and her colleagues recently launched a project to do this in about 100 homes in Texas, but the results have not yet been published.
If deployed on a large scale, it could one day help power grid operators manage surplus electricity, and homeowners could even receive discounts on their payments or electricity bills as an incentive to participate in load balancing efforts. Experiments of this kind, focusing on other appliances such as washing machines and hot water tanks, have been ongoing. This is already happening on a large scale in the UK and other countries.One obstacle, Mathieu points out, is that thermostat and heat pump technologies vary widely, each using different software, and the infrastructure to remotely control thousands of heat pumps has not yet been deployed.
Climate change is unlikely to disable heat pumps, despite the effects of strong winds and extreme temperatures, Callaway argues. It’s more a matter of system design and anticipated contingencies. But Vangheli stresses that it’s worth thinking about climate change scenarios now. Having spare capacity and back-up technology in place could help ensure that decarbonized heating systems aren’t vulnerable.
