Tag Archives: climate change

How hot was Sept 2023?

September 2023 set a record for a monthly anomaly, but when you read something that says it was surprising, outrageous, crazy, etc., you are being misled. As far as I’m concerned, this is the media making matters worse. A new record anomaly like September is expected, and, in fact, it will happen again. Suggesting that scientists didn’t know this implies that they aren’t credible. Please read the full argument here and while you are there, subscribe to my Substack Briefed by Data. You can subscribe for free and get data-based articles right in your inbox.

Summary from NOAA, which has the data available:

The September global surface temperature was 1.44°C (2.59°F) above the 20th-century average of 15.0°C (59.0°F), making it the warmest September on record. September 2023 marked the 49th-consecutive September and the 535th-consecutive month with temperatures at least nominally above the 20th-century average. September 2023 was 0.46°C (0.83°F) above the previous record from September 2020, and marks the largest positive monthly global temperature anomaly of any month on record. The September 2023 global temperature anomaly surpassed the previous record-high monthly anomaly from March 2016 by 0.09°C (0.16°F). The past ten Septembers (2014–2023) have been the warmest Septembers on record.

How hot was August 2023?

From my post of the same name on Briefed by Data. Figure 1 shows that the August 2023 anomaly was a record for August by a half degree Fahrenheit, or about a 30% increase over the previous record in 2016. Here is what NOAA has to say about August 2023:

The August global surface temperature was 1.25°C (2.25°F) above the 20th-century average of 15.6°C (60.1°F), making it the warmest August on record. This marked the first time an August temperature exceeded 1.0°C (1.8°F) above the long-term average. August 2023 was 0.29°C (0.52°F) warmer than the previous August record from 2016, but the anomaly was 0.10°C (0.18°F) lower than the all-time highest monthly temperature anomaly on record (March 2016). However, the August 2023 temperature anomaly was the third-highest anomaly of any month on record.

Links to the data are in the post, plus two other graphs.

How does an increasing mean impact maximum temperatures?

In my recent Briefed by Data post How rising mean temperatures affect maximums I use a simple simulation to help understand climate change and the impact increasing mean temperatures have on maximum temperatures. For example,

We expect a roughly 50% increase in summers with temperatures over 100°F over the first 50 years of the rising temperature scenario, followed by a 5-fold rise during the next 50 years. One important thing to note is that, compared to no change, the slow rise in temperature won’t be felt as much in the first 50 years. In the scenario of rising temperatures, even the difference between the first 50 and the second 50 is tripled. In essence, nothing is noticeably bad until it is.

Read more over at Substack and consider subscribing to my newsletter Briefed by Data.

How hot was June 2023?

From NOAA’s June 2023 Global Climate Report:

June 2023 set a record as the warmest June for the globe in NOAA’s 174-year record. The June global surface temperature was 1.05°C (1.89°F) above the 20th-century average of 15.5°C (59.9°F). This marked the first time a June temperature exceeded 1°C above the long-term average.

By definition we don’t officially know if June 2023 was an El Niño month (hence the black bar in the graph) but it was emerging and likely will be one. More about June 2023 on my Briefed by Data site.

How hot was May 2023?

From the NOAA May 2023 Global Climate Report:

May 2023 was the third-warmest May for the globe in NOAA’s 174-year record. The May global surface temperature was 0.97°C (1.75°F) above the 20th-century average of 14.8°C (58.6°F). The past nine Mays have ranked among the 10 warmest on record. May 2023 marked the 47th consecutive May and the 531st consecutive month with global temperatures, at least nominally, above the 20th-century average.

Note that May wasn’t far off a record. This shouldn’t be a surprise because

Global ocean surface temperature hit a record high for May, which marks the second-consecutive month where ocean surface temperatures broke a record. On June 8, NOAA’s Climate Prediction Center announced an El Niño Advisory alert status; weak El Niño conditions emerged in May as above-average sea surface temperatures strengthened across the equatorial Pacific Ocean. El Niño conditions are now present and are expected to gradually strengthen into the Northern Hemisphere winter 2023–24.

El Niño periods are much warmer. See the Briefed by Data post The Three Trends of Climate Change. The time series data is at the top of the page.

How hot was April 2023?

From NOAA’s April 2023 Global Climate Report:

April 2023 was the fourth-warmest April for the globe in NOAA’s 174-year record. The April global surface temperature was 1.00°C (1.80°F) above the 20th-century average of 13.7°C (56.7°F). The 10 warmest April months have occurred since 2010. April 2023 marked the 49th consecutive April and the 530th consecutive month with global temperatures, at least nominally, above the 20th-century average.

Highlights:

Global ocean temperatures set a record high for April at 0.86°C (1.55°F) above the long-term average. This marked the second-highest monthly ocean temperature for any month on record, just 0.01°C (0.02°F) shy of the record-warm ocean temperatures set in January 2016.

The Southern Hemisphere experienced its warmest April and warmest month on record.

The data is available at a link on the top of the page.

Where can we get high-res temp data?

The image here is the annual average temperature anomalies in 2022 compared to  the 1981-2010 baseline average. The image uses data from the Berkeley Earth high-resolution data set as noted in the article Introducing the Berkeley Earth High-Resolution Dataset by Robert Rohde (3/28/2023):

The new Berkeley Earth High Resolution Data Set improves upon the previous version by providing a 0.25° x 0.25° lat-long resolution (approximately 30 km at the equator), which is four times higher than the previous 1° x 1° resolution. This allows for a more accurate representation of small-scale temperature variations, particularly in areas where geography is changing rapidly, such as coastlines and mountainous terrain.  It also does a better job of capturing ocean variations related to currents and other structures.  The new gridded data product derives its information from approximately 50,000 weather stations and more than 450,000,000 ocean temperature measurements, providing excellent coverage of the Earth’s surface.

The good news is the Berkeley Earth makes this data available on its data page. Read more about the data and processing in the article.

How warm is the sea surface?

Climate Reanalyzer has an interactive time series chart of ocean temperatures. The dark black line at the top is the  current year and shall we say we are in uncharted waters.  It would  be nice if this graph was colored by ENSO status in the way NOAA has a global temperature graph by ENSO status. Why does this matter? According to a Guardian article:

La Niña periods – characterised by cooling in the central and eastern tropical Pacific and stronger trade winds – have a cooling influence on global temperatures. During El Niño periods, the ocean temperatures in those regions are warmer than usual and global temperatures are pushed up.

After a few years of La Niña we’ll see what El Niño will do to global temps.

 

How fast are seas rising?

The NASA post NASA Uses 30-Year Satellite Record to Track and Project Rising Seas (3/17/2023) has this to say (with calculus language):

Since satellites began observing sea surface height in 1993 with the U.S.-French TOPEX/Poseidon mission, the average global sea level has increased by 3.6 inches (9.1 centimeters), according to NASA’s Sea Level Change science team. The annual rate of rise – or how quickly sea level rise is happening – that researchers expect to see has also increased from 0.08 inches (0.20 centimeters) per year in 1993 to 0.17 inches (0.44 centimeters) per year in 2022. Based on the long-term satellite measurements, the projected rate of sea level rise will hit 0.26 inches (0.66 centimeters) per year by 2050.

Interesting fact in the article:

The 2022 increase was less than the expected annual rate because of a mild La Niña. During years with an especially strong La Niña climate pattern, average global sea level can even temporarily drop because weather patterns shift in a way that leads to more rainfall over land instead of the ocean.

NASA Sea Level page with data.