Too Little and Too Much

Robert Hunziker quotes an estimate of $200 trillion needed to achieve zero emissions by 2050. Meanwhile, the "production gap" is expected to be twice the level of fossil fuels by 2030 than what would be consistent with the 1.5 degree warming limit.

Increasing Rate of Warming

An article published in Oxford Open Climate Change called "Global warming in the pipeline" finds that the 

decline of aerosol emissions since 2010 should increase the 1970–2010 global warming rate of 0.18°C per decade to a post-2010 rate of at least 0.27°C per decade. Thus, under the present geopolitical approach to GHG emissions, global warming will exceed 1.5°C in the 2020s and 2°C before 2050.

Lead author James Hansen: 

The 1.5-degree limit is deader than a doornail. And the 2-degree limit can be rescued, only with the help of purposeful actions.

Uncharted

An article published in BioScience updates "vital signs" for the planet. There are now 20 of 35 at record extremes.

The effects of global warming are progressively more severe, and possibilities such as a worldwide societal breakdown are feasible and dangerously underexplored.

[W]e advocate for reducing resource overconsumption; reducing, reusing, and recycling waste in a more circular economy; and prioritizing human flourishing and sustainability. We emphasize climate justice and fair distribution of the costs and benefits of climate action, particularly for vulnerable communities. We call for a transformation of the global economy to prioritize human well-being and to provide for a more equitable distribution of resources. We also call to stabilize and gradually decrease the human population with gender justice through voluntary family planning and by supporting women's and girls' education and rights, which reduces fertility rates and raises the standard of living.

Missing the Present

This year is likely to be the warmest on record--exceeding the years 2016 and 2020. Berkley Earth estimates there is a 55 percent chance the temperature anomaly for 2023 will reach 1.5 degrees Celcius.

And as Émile Torres points out, this summer will be among the mildest for the rest of our lives.

In a few decades, we'll look back on 2023 as the calm before the storm, when life was still fairly normal. Our children may even remember this year with nostalgia, as a fading glimpse of a world they never got to know — one marked by relative stability rather than environmental chaos and catastrophic collapse. For all the horrors of this summer, we should perhaps take a moment to appreciate it, because this may be as good as it gets moving forward.

Climate Deaths

A study published in Energies estimates the toll from future warming.

Several studies are consistent with the "1000-ton rule," according to which a future person is killed every time 1000 tons of fossil carbon are burned (order-of-magnitude estimate). If warming reaches or exceeds 2 °C this century, mainly richer humans will be responsible for killing roughly 1 billion mainly poorer humans through anthropogenic global warming, which is comparable with involuntary or negligent manslaughter.

Hottest Month (Yes, So Far)

The Copernicus Climate Change Service announced that last month is the warmest on record by a wide margin.

July’s global average temperature of 16.95 degrees Celsius (62.51 degrees Fahrenheit) was a third of a degree Celsius (six tenths of a degree Fahrenheit) higher than the previous record set in 2019.

The month was 1.5 degrees Celsius (2.7 degrees Fahrenheit) warmer than pre-industrial times [and] 0.7 degrees Celsius (1.3 degrees Fahrenheit) hotter than the average July from 1991 to 2020.

Days in July have been hotter than previously recorded from July 2 on.

Update (September 6):  The World Meteorological Organization announced that this summer was the warmest for the Northern Hemisphere. 

Last month was not only the hottest August scientists ever recorded by far with modern equipment, it was also the second hottest month measured, behind only July 2023.

Update (October 9):  And now the record for the largest monthly anomaly.

Last month's average temperature was 0.93 degrees Celsius (1.7 degrees Fahrenheit) above the 1991-2020 average for September. That's the warmest margin above average for a month in 83 years of records kept by the European Space Agency's Copernicus Climate Change Service.

Copernicus calculated that the average temperature for September was 16.38 degrees Celsius (61.48 degrees Fahrenheit), which broke the old record set in September 2020 by a whopping half-degree Celsius (0.9 degrees Fahrenheit).

Update (November 10):  Climate Central reports that the twelve months from November 2022 to October 2023 were the warmest in recorded history. 

[A]verage global temperatures during that period were roughly 1.32º Celsius (2.4º Fahrenheit) above preindustrial averages. As a result, roughly nine out of ten humans alive experienced at least 10 days over the past 12 months during which high temperatures would have been unlikely if not for climate change.

 

Hottest Day ... So Far

The global mean temperature measured 62.62 degrees Fahrenheit on July 3 exceeding the previous record of 62.46 degrees set in August 2016. I would guess this record will be broken in considerably less than seven years.

One reason is that the carbon dioxide concentration in Mauna Loa was 424 parts per million in May. 

That’s more than 50% higher than before the industrial era began roughly 250 years ago and 3 parts per million higher than what federal scientists counted in May 2022. It represents the fourth-largest annual increase since the National Oceanic and Atmospheric Administration started its tally 65 years ago.

This trend is pushing the Arctic toward ice-free summers as soon as the 2030s. 

The loss of summer sea ice would trigger a feedback loop known as "Arctic amplification" with the dark ocean absorbing more solar heat and causing additional planetary warming.

And the emergence of the El Niño pattern in the Pacific Ocean only intensifies extreme weather events.

The effects of El Niño tend to peak during December, but the impact typically takes time to spread across the globe. This lagged effect is why forecasters believe 2024 could be the first year that humanity surpasses [warming of] 1.5 degrees Celsius. Global average temperatures in 2022 were 1.1 degrees Celsius warmer when compared to the late 19th century.

Update (July 5):  Well, that was fast.

On Tuesday, the global average temperature peaked at a new all-time high of 17.18 degrees Celsius [62.92 degrees Fahrenheit] as regions worldwide—from Asia to Africa to the U.S. South—reeled from dangerous heatwaves.

Update (July 6):  Apparently, Wednesday tied Tuesday's record. Brian McNoldy:

It's so far out of line of what's been observed that it's hard to wrap your head around. It doesn't seem real.

Update (July 7):  The new (unofficial) record, set Thursday, is 63.01 degrees Fahrenheit. 

Update (July 15):  No new global records yet, but the southwest U.S. is blazing.

Nearly a third of Americans were under extreme heat advisories, watches and warnings. The blistering heat wave was forecast to get worse this weekend for Nevada, Arizona and California, where desert temperatures were predicted to soar in parts past 120 degrees Fahrenheit (48.8 degrees Celsius) during the day, and remain in the 90s F (above 32.2 C) overnight.

Phoenix marked the city’s 15th consecutive day of 110 degrees Fahrenheit (43.3 degrees Celsius) or higher temperatures on Friday, hitting 116 degrees Fahrenheit (46.6 degrees Celsius) by late afternoon, and putting it on track to beat the longest measured stretch of such heat. The record is 18 days, recorded in 1974.

Update (July 26):  World Weather Attribution claims that this month's record heat would be "virtually impossible" in the absence of anthropogenic climate change. 

Update (September 10):  Phoenix continues to set new heat records for 110 degree Fahrenheit days.

[Saturday] was the 54th day this year that the official reading at Phoenix Sky Harbor Airport made the mark, eclipsing the previous record of 53 days set in 2020.

In July, Phoenix also set a record with a 31-day streak of highs at or above 110 F (43.3 C). The previous record of 18 straight days was set in 1974.

Update (July 24, 2024):  Sunday and Monday are being described as record-breaking days for global mean temperature. The values are given as 17.09 degrees Celsius (62.76 degrees Fahrenheit) and 17.15 degrees Celsius (62.87 degrees Fahrenheit). Apparently, last year's record was revised to 17.08 degrees Celsius for July 6.

And it looks like Tuesday tied Monday.

Update (July 25, 2024):  I guess Monday was revised to 17.16 degrees Celsius (62.89 degrees Fahrenheit) and so Tuesday is the second warmest day on record.

Update (September 4, 2024):  Phoenix is on the verge of breaking last year's record and has also set another record with 100 consecutive days of 100 degree Fahrenheit temperatures.