It took humans from 1800, the date many climate models use as the beginning of the Industrial Revolution, until about 2016 to emit enough greenhouse gas to raise the global mean temperature 1.0ºC above pre-industrial levels.
Subsequently, it has taken just seven years to push our current temperature up to almost 1.2ºC above pre-industrial levels. That means that the rate of temperature change in the past seven years is almost 10 times greater than the average rate was in the previous 216 years. Represented as a line on a graph, the recent jump in temperature would appear to go almost straight up.
Note that emissions themselves haven’t risen at a similar rate, although their rise has accelerated since 1950. The recent “spike” in temperature, especially noticeable in 2023, is partly due to a lag between the time greenhouse gases enter the atmosphere and the time temperatures go up, so the cumulative emissions of previous decades are driving today’s warming. Additional factors, including the 2023 El Niño, which contributes to periodic, oscillating rises in global temperatures, and the increased amount of the greenhouse gas water vapor that our warmer atmosphere holds, also contribute.
In 2015, the UN’s COP21 Paris Climate Accords garnered pledges from most of the world’s countries to cut their emissions so as to limit global temperatures from rising above 2.0ºC, which is considered to be a dangerous, “do not cross” warming threshold. But with extreme climate-conditioned events already impacting them, many island nations pushed for faster emissions reductions, and the 2021 COP26 meeting in Glasgow adopted the “aspirational goal” of keeping temperatures below 1.5ºC. Countries pledged to meet the new goal, although it was clear to many observers that it might not be fully met before 2100, the agreement’s cutoff year. But just coming close to that goal would definitely ease impacts.
Well, the World Meteorological Organization and other scientific bodies now predict, with “high confidence,” that we’ll permanently pass the 1.5ºC threshold in the early 2030s. In fact, we have already passed it for short periods. The first time was for a few days in 2015, a year when the El Niño condition, which adds to global temperature, was active. Then, in 2023, the BBC reports, we passed it for 86 days, or about one-fourth of the entire year. We’re on the way to jumping up from our current 1.2ºC temperature level to 1.5ºC within a decade.
To make matters worse, the UN’s 2023 IPCC report tells us there is a 50% chance we’ll surpass the even more perilous 2.0ºC threshold by 2050, and an 80% chance we’ll do so by 2060.
What do these numbers say about the anticipated impacts?
Considering the apparent “quantum leap” in the frequency and severity of impacts in the hot summer of 2023, the numbers do not bode well. If the rate of impacts roughly correlates with temperature change, earth systems such as the cryosphere (ice), ocean food productivity and global forests, as well as agriculture and possibly civilization itself, would likely cross irreversible tipping points toward collapse as early as 2035, and certainly by 2050.
However, anticipating whether there is such a direct correspondence between temperature rise and impacts is difficult, if not impossible, because of the nonlinear, often random nature of impact occurrence and our limited means of quantifying and expressing overall impacts. Certainly one approach to measuring impacts is economic: Climate change will cost the global economy X dollars by the year Y. We will look at some projections in the upcoming articles on this topic, but we must keep in mind that economic statistics usually fail to express the costs in terms of human lives lost or impoverished, community dissolution, ecosystem damage and ecosystem service loss and so on.
A lurking danger in all of this is something called the “doom loop.” As argued in a 2023 position paper by the British Institute for Public Policy, a downward-spiraling doom loop would force us to spend so much money trying to rectify the impacts of climate change that we would fail to spend what’s needed to address its root causes — a topic we’ll take up in our next post on Firebird Journal.
Editor’s Note: A version of this article appeared previously in other publications as part of an ongoing series called “Your Ecological House,” written by Philip S. Wenz, the publisher of Firebird Journal.