"Borrowed time": As we shatter temperature records, experts worry we're in "uncharted territory"

Our rapidly heating planet is regularly shattering records these days. December through February was so warm — in fact, the hottest winter on record in the U.S. — it's been described by some climate experts as a "lost winter." Last year also set new records for global surface temperature, hottest summer and ocean heat content. Perhaps most ominously, the world averaged temperatures 1.4º C higher than pre-industrial levels during those 12 months.

Now the European Union's Copernicus Climate Change Service revealed that March 2024 was 1.68º C warmer than pre-industrial times, prompting one NASA scientist (Dr. Gavin A. Schmidt) to warn the BBC that humanity is now in "uncharted territory." This is the tenth month in a row to be the warmest on record for its respective month of the year.

Schmidt, the director of Nasa's Goddard Institute for Space Studies, told Salon that "the long term changes in climate are already having effects on the probabilities of some extreme events (heat waves, intense rainfall, soil moisture drought, etc.)" Schmidt's observation was echoed by the Copernicus deputy director Samantha Burgess, who said in a statement that although the Paris climate accord threshold has not been breached (because the figure has not sustained at that level for a full year), "the reality is that we’re extraordinarily close, and already on borrowed time."

Nevertheless scientists warn that this should not be misconstrued as meaning every future month will be hotter than the one that came before it. The latest series of months have been the hottest ever recorded, yet in itself that does not guarantee that the upcoming months after the summer will also break records or that extreme weather events will worsen. Dr. Michael E. Mann, a climatologist from the University of Pennsylvania, unpacked this for Salon.

"If the current model predictions are correct, and we transition toward La Niña over the next few months, we’ll actually see a return toward the trend line" in terms of global temperatures, Mann said. Within the ENSO (El Niño and the Southern Oscillation) pattern in the tropical Pacific, El Niño is the warm phase and La Niña is the cool phase, meaning La Niña can mitigate some of the deleterious effects of climate change. Even so, when La Niña subsides, the overall trend line of rising global temperatures will continue unless humans reduce their carbon emissions.

The bottom line according to Dr. Mark Serreze, director of the National Snow and Ice Data Center (NSIDC), is that "we need to be careful about reading too much into one or two years" given the ENSO cycle's impact on recent temperatures and its likely lowering of future temperatures. "The situation (the temperature trend) is bad enough as it is — there is no reason to sensationalize."

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"It’s the trend line we should be talking about and worried about," Mann also said. "It will breach 1.5º C in a decade in the absence of concerted efforts to lower carbon emissions."

Schmidt framed understanding the trend line in the broader context of the questions being discussed in the scientific community. He identified two main points: First, scientists want to see if long-term climate change projections remain on track; and second, scientists want to comprehend the anomalous heat of the recent few months.

"The answer to the first is yes – in general, and the answer to the second is still ambiguous," Schmidt said. "There is good evidence that the last 12 months have been particularly anomalous, for reasons that will include El Niño, and aerosols, and internal variability etc. but the exact breakdown is still unclear, but depending on what we find, it might have implications for the first question."

Regardless of why exactly temperatures are rising — how much of it is the ENSO cycle and how much of it is climate change — scientists agree that climate change is, at the very least, a significant contributing factor. As such, humanity is in a sense already past an important threshold in terms of what we should expect from our planet as a result of our carbon emissions.

Dr. Twila Moon, the deputy lead scientist and science communication liaison at the NSIDC, says that humanity is "already in uncharted territory" when it comes to climate change because "extreme and record-setting weather events are happening more often, impacting local communities [and] international economics." Moon expects there will be increasingly dire effects from climate change such as rising sea levels (which cause coastal erosion and create problems with sewage and drinking water system) and prolonged wildfire seasons (including worsened wildfire smoke and longer heat waves).

In addition to humanity being in "uncharted territory" with its global temperature records, our species is achieving other dubious distinctions. Dr. Kevin Trenberth, a distinguished scholar at the National Center for Atmospheric Research, said that "other announcements have noted the record high increases in greenhouse gases: carbon dioxide, methane and nitrous oxide, so that the cause of global warming (us) has not abated at all in spite of many valuable efforts." He added that China and India remain two of the major culprits, explaining why "climate change will continue, largely unabated for now."

Trenberth added, "In the USA, watch out for a vigorous hurricane season in the Atlantic, affecting the eastern seaboard."

Moon had specific advice for populations everywhere, since all of us will have to cope with climate change.

"It is critical that we act now both to make changes to our buildings, community connections and economic systems to be more capable of dealing with extreme events (e.g., insulating buildings help to keep people comfortable in heat and cold, while also save energy/money) and we act to decrease creation of heat-trapping gasses from burning oil, coal, gas and other activities," Moon said.