What was the Hunga Tonga eruption, and is it causing our extreme summer heat?

Good morning. In the big picture, Houston’s overall forecast remains largely the same. After some lovely, drier air we’re back into high humidity and high heat through the weekend. By Monday, we’ll be watching the Gulf of Mexico with bated breath, to see whether a tropical system brings much needed rainfall to the Upper Texas coast. I think that’s still about a 50-50 proposition.

Before jumping into the forecast I want to answer a question I’ve received many times in recent weeks about this summer, which has seen record temperatures in the Gulf of Mexico, alarmingly low levels of sea ice, and extreme heat around much of the world. NASA recently concluded that July 2023 is the planet’s hottest month in the reliable global temperature record, which dates back to 1880. The question I’m getting is, could this be caused by the large amount of water vapor injected into the upper atmosphere by the eruption of the Hunga Tonga volcano in December 2021, in the Southern Pacific Ocean?

Earth’s average temperature this year is far above that of previous years. (Berkeley Earth)

Typically, big volcanic eruptions send large amounts of sulfur dioxide into the stratosphere, which reflects sunlight and cools the climate. By contrast, the Hunga Tonga eruption also produced large amounts of water vapor, a potent greenhouse gas. So is this the culprit for extremely warm temperatures this year?

As always with climate, the answer is complex, and nuanced. However, the Berkeley Earth non-governmental organization recently published an analysis that I think captures several of the factors that led to this summer’s heating. Principally, there is human-caused global warming; but there are a number of other factors that have contributed this year, including a switch to El Niño, the Solar cycle, the Hunga Tonga eruption, and a reduction in marine fuel pollution that has led to clearer air. All of these factors, layered on top of global warming, have really goosed temperatures this year.

Factors contributing to a warming planet over the last 10 years. (Berkeley Earth)

As the report notes, the effect of the Hunga Tonga eruption is probably relatively small, but it likely has added some warmth to the planet after injecting about 150 million tonnes of water vapor into the stratosphere. It will take a few years for this plume to dissipate. Please note that I realize that the mere mention of climate change gets some readers really upset. I’m sorry, but on a weather website it is occasionally necessary to mention that the planet is warming, and discuss potential causes. If you feel compelled to get nasty in the comments below, your IP address will be banned. Most readers have been polite in previous discussions, agreeing to disagree, and I appreciate that.

Now, on to the forecast.

Thursday

The dry air, sadly, is gone. And so we welcome back high temperatures in the low 100s, humid air, sunny skies, and light southerly winds. Nighttime lows are around 80 degrees. We all know the drill.

Friday

More of the same.

Saturday and Sunday

The weekend looks sunny and hot, with high temperatures again of around 100 degrees, or perhaps a tick or two higher. There’s a slight chance of some rain on Sunday afternoon, but I wouldn’t hold your breath.

This image compares the GFS forecast and European model forecast for rain accumulation next week. (Weather Bell)

Next week

So what’s going to happen next week with that tropical wave? Unfortunately the global models remain divided about its outcome. The Global Forecast System, or GFS model, keeps the low to the south of the greater Houston area, along with much of its rainfall. The European model, however, brings the low much closer to our region, and delivers a healthy dose of rainfall during the middle of next week. I think both scenarios are plausible, so I don’t have confidence in making a forecast just yet. If we do get some cloudy, rainy days, it will knock high temperatures back into the 90s. Please clap.

70 thoughts on “What was the Hunga Tonga eruption, and is it causing our extreme summer heat?”

  1. I feel more confident seeing that the Euro model shows rain. Euro model normally nails it, for most part

    • The problem, in this case, is that there is not a tremendous amount of support for this in the ensembles. I want to believe, but I’m not convinced.

  3. Thank you for speaking the truth about the weather and the Climate Change that is causing it. Even when we don’t like hearing the truth (…it’s hot out…).

  5. Thanks for telling it like it is. The climate is warming, whether you like it or not. The faster we face facts, the better off we will all be. The ostrich school of conflict avoidance will not help us.

  8. I’ve read that CO2 is 0.04% of the green house gases. Assuming that is true, I struggle to follow how humans have such an impact on climate change on such a small weighting of the pertinent gases. What am I missing?

  9. I appreciate your including a reference to a reduction in marine fuel pollution. It is not often that I hear any reference to reduction in air pollution, specifically the reduction in particulate mater (PM), as a contributor to increased atmospheric heating. One of the five air pollutants that the EPA has focused on for the past 50 years is PM. And we’ve don a pretty good job of controlling emissions of PM. Ironically, though, reducing the amount of PM emitted into the air by numerous sources – power plants, diesel engines, industrial facilities, etc – has also reduced the reflectivity of the our atmosphere and results in more radiation reaching to lower altitudes. So there’s good news and bad news, right? Less PM is good but more radiation, more heating is bad. Another way to look at it is that the PM that had built up in the atmosphere during the last coupla centuries actually served to cushion the planetary heating that has been ongoing essentially since the last ice age. And we have been successful in lowering that type of air pollution. It’s like we can’t win for losing.

    • I always take less pollution as good news, but this is yet another example of the complexity of climate.

      • Wow! So you include couple of insignificant, non-provocative references to “climate” in a weather forecast, only in an attempt to be responsive to you readers, and BOOM! More than fifty folks have opinions that they believe need to be shared. Good for you for trying to be informative, but sorry for the uninvited feedback.

        I can’t wait to see how many more post this inoffensive response inflames.

    • I think we need more roads, strip malls, and buildings. We ignore the fact that globally we’re clear cutting trees to just build something that retains heat, reduces the natural cooling effect, and emits more pollution than scrubbing the air. Ride a motorcycle or drive with your windows down, when you enter a wooded area the temperature drops significantly. Hit the strip malls, gas stations and commercial areas, it hot as blazes.

    • PM also causes critically important health effects … increased PM levels are associated with an increase in cardiovascular events (e.g., ER visits for heart attacks).

      So indeed – a mixed effect. If memory serves, we experienced some noteworthy heating in the days after 9/11 when air travel was shut down.

  10. Thank you for your remarks about climate change. To argue that the planet isn’t warming ignores the facts. We are able to measure this, and the results aren’t good.

    If one must contradict science, a better argument is to contend that humans are not the primary cause. I believe this argument is also flawed for many reasons, but at least it has some merit.

    In any case, waging nasty attacks has no place in civil discourse. It is essential that we all enforce this norm.

    • Science is constantly contradicted as we learn more. Enforcing a “norm” unfortunately smacks a bit of censorship. There are many opinions about why and how climate changes, and a norm or a consensus does not ensure that we reach the truth. The best scientists keep an open mind, and are willing to forego a prior conclusion when the evidence leads us elsewhere.

      • The best scientists do that, sure. But keeping an open mind doesn’t necessarily mean that the evidence or conclusions are in question. The evidence we have now, which is overwhelming, is that humans are the primary cause for climate change. One of the best examples of this is, if you remove human influence to the climate, then we should be in a cooling phase right now. Instead, we’re breaking records on the other side.

  11. Thanks for responsible reporting…friends retired from NASA and I where talking Tonga last week…keep up the great work.

  12. Thank you for addressing and clarifying the Hunga Tonga Eruption. I value your insight and advice!

  14. Thank you guys as always. Factual weather reporting is rare and I appreciate the fact that you guys always report that.

    While I agree climate is warming I also think that the human influence on a macro level is minimal and if it exists there is a calculation on the benefits of fossil fuel use that also has to take place.

    I also think that not being able to have a serious discussion

  15. I believe the correct term is bated breath, from abated breath, meaning holding the breath waiting to see what transpires.

  16. This is super cool info guys. Appreciate the time and effort to put it together. I was surprised to see cleaner air as a contributing factor to hotter climate.

    That seems contrarian to me, who knows little on the subject and refuses to read too much into it do to the polarizing nature of the topic. Can you guys walk me through that or speak to it in a future post?

    • It’s simply a matter that putting sulfur pollutants into the atmosphere increases its reflectivity, and therefore blocks a tiny bit more sunlight from reaching the surface of the planet.

  17. I especially enjoyed this post. I’ve never heard of Berkeley Earth, and I think I’ll read more of their writing.
    I also like your references to climate change. You approach it as a simple acknowledgement to how climate change affects our local weather.

  22. A balanced view on the subject of a warming climate is always a welcome relief. Too many folks are more interested in pushing a narrative based on closed self-reinforcing loops rather than having a discussion supported by data. Thank you.

  23. Thank you for acknowledging climate change. You can either give fair and accurate weather information, or you can deny fundamental facts about the planet, but not both. 🙂

  25. Thank you as always for the complete, science based reporting. As a child of two retired NASA scientists, I appreciate it. Things are changing and we cannot ignore that, no matter the cause.

  26. Thank you for putting out such an informative newsletter. Read it very day. I don’t think the issue is about global warming necessarily. There really shouldn’t be any debate about that. Global warming (and cooling) and it’s cyclical nature has no doubt occurred on the planet Earth since the beginning of time. i think it’s the “man-made” part get gets some upset. I am not aware of any definitive study that has demonstrated this – and if so, to what extent. As you have correctly pointed out, causation if more than likely, multifactorial. Again, thank you for most informative newsletter! Ps. Great App by the way!

    • “Catastrophic man made” is the problem, as are the political “solutions”.

      Also, as he points out, reducing pollution increases temperature, and pollution reduction over the last 50 years is also “man-made.”

  28. Thank you so much for what you do. My wife even got me one of your caps which I proudly wear. Regarding you reference to climate change, thanks for that as well. I’m almost 70 years old and spent almost 40 years working for the largest energy company on this planet so you can probably figure what side of this issue I reside on. I remember when the pundits said we were going to enter another ice age because of the same emissions that different pundits say will cause us to heat the planet up to an unlivable status. Go figure. Industry in the West has generally done its part to work toward solutions by reducing emissions. But there are far more people on this planet than there were 40 years ago particularly in SE Asia, India, and China. They need to step up to the plate so to speak as well. Our political “leaders” on both sides of this matter are very short on realistic solutions. For example non of them want to look at nuclear which is practical and efficient and can work if only given a realistic chance. Thanks for your hard work

    • While I agree with most of what you have said, including nuclear to be a clean option, I do have to point out that nuclear energy remains a huge concern for several reasons. The first is that the dollar will always win out over conscience and carefulness. Businesses in the US cannot be relied upon to not cut corners on safety if it costs them a lot of money. The second issue is tied to the first, in which natural, unforeseen disasters cripple and compromise nuclear plants. Even Japan, who is extremely conscientious and exacting in their building codes suffered an enormous disaster with their nuclear plant from the Tohuko earthquake and tsunami in 2011. The third, as we have seen in the Ukraine, is that nuclear plants become a target for terrorism. The devastating effects of a nuclear leak are longstanding and irrevocable.

    • Try to remember that energy in the U.S. is private, for-profit industry doing whatever earns the most profit. Nuclear costs billions, takes a decade to build, then always ends up being overdue and over budget. And in the end is very expensive per megawatt of energy produced. While solar is cheap. What there should be more of is geothermal which can be produced anywhere. You just have to drill for it. They drill to some extreme depths for petroleum. Fortunately, major breakthroughs in drilling tech and enhanced geothermal methods have occurred recently.

      What I don’t get is how it is more profitable to drill for oil, extract it, pump it or haul it somewhere to be sold, bought, refined, then sold and hauled somewhere else to burn for electricity, than it is to just produce and sell electricity. Especially when you consider the many middlemen in petroleum that also make a profit.

  30. A High Pressure to the North in the Winter equals cold. So, a High Pressure to the South in the Summer equals hot.

  31. There are trade offs with everything and wind/solar just won’t produce enough for society to function. And yet nuclear energy is the cleanest energy and basically prohibited. I have read that new technology allows for reactors to be the size of car or smaller only having to be refueled once about every 25 years with the heat exchange occurring underground similar to geothermal. An added bonus is the amount of material required is smaller than a suitcase. This allows for storage until time to load a space craft and aim at the sun to dispose of it. Clean and no pollution. How many power plants could be built in remote areas to power pretty much everything?

    • Nuclear is not prohibited. A new reactor just opened in Georgia. After over a decade of building, delays, budget overruns, etc. Which is the reason few are built. Along with the fact that Nuclear is very expensive electricity per megawatt. VS wind & solar.

  32. I am glad you guys are real people doing an admirable job of bringing us weather information and personal glimpses of your experience and education concerning weather. Thanks for being kind and good at what you do.

  33. Good on the humidity returning. This insanely dry air is driving my sinuses crazy! Not to mention getting shocked all the time by the static. I hope it gets up to at least 70%. The more the merrier (for me anyway) 🙂

  34. When I read comments ignoring the effect we have made to the planet in terms of climate and environment, I fear one additional effect is that people are getting intellectually dimmer. The idea that China is “wisely going their own way’ when it is categorically clear that China contributes massively to the overall negative climate with their polluting emissions is patently absurd. I fear for the future of the human race when I see those kind of ignorant attitudes. expressed.

  35. Have lived here my entire 61.75 years, August is hot, has always been hot, and will probably…get this…always be hot. If you don’t like it, this probably isn’t the place for you. We’re inconsequential, just ask the dinosaurs.

  36. Thanks for the visual on heating/climate change models. Super helpful to see the factors collected together. I think of climate/weather as the same thing but only different by the measure of time and duration. Both are relevant when planning for future mitigation. On a different note, I am sure meteorologists love seeing two major weather models showing completely different outcomes during a drought, then asked to predict rain chances for an upcoming week. Not a fun moment! Ugh!
    I read the NWS forecast discussions daily (nerdy I know), so I now am realizing what forecasters mean when they say the “models are coming into alignment”. So in the case of next week’s sorely needed precipitation forecasters will keep running these models every 12(?) or so hours to see if the models agree. Personally, I LOVE the European model’s rain outcomes, but that doesn’t mean it will happen. Still, we can HOPE we get rain! BTW: Please show a sliding model update of the GFS/ European in a future post. That was really a neat map! Thanks for including it.

  37. If your reliable global temperature range data only goes back to 1880, how can you possibly posit that the earth is warming? Since 1880?

    • Because we have mountains of data from prior to 1880 to work with. Here’s NASA’s explanation on how that works. The short version is that direct, recorded, verified global temperature measurement began in 1880, but there are a whole pile of reliable methods to measure and infer temperature from what are called “proxy records”—fossil evidence, tree rings, pollen counts, ice or soil core analysis, and many, many others. There is reliable data about Earth’s temperature going back as far as we have fossil records.

  38. Growing up (I am 60) I was always told when talking to folks you don’t know stick to topics that are innocuous like say the weather….funny how that changes. Thanks for the additional info on the Hunga Tonga eruption Eric it is always interesting to hear and learn of all the complexities that is weather and climate. Thanks for all you do!

  39. Great overview and explanation of this crazy hot summer. Climate change must be included in any conversation regardless of the overall impact from it. Hopefully it reminds us all to be responsible stewards of this earth so it is not intolerable for our kiddos. Thank you for bringing us our daily weather report.

  40. Your discussion of volcano-influenced weather took me back to my days in Richmond, Virginia, in the 1960s. There was an amateur meteorologist named Louis Rubin who predicted unusual weather events based in part on volcanic activity. I recall a monster snowstorm in late January 1966 he had accurately predicted. I worked for a radio station news department at the time and we actually had prepared for the storm with four-wheel drive vehicles and staffing changes. I found an interesting article about Rubin which can be read at this link: https://discover.hubpages.com/education/The-Fascinating-Predictions-of-Louis-D-Rubin

  41. A great admirer of your columns, but . . . It’s not “baited” breath (“bait ” somehow attached to breath, if that can be imagined), it’s “bated” (as in shortened; cf. “unabated”) breath!

  42. In 2001 the local weathermen were really hopeful that a tropical system would come in and bust the drought that year. Tropical Storm Allison surely did bust the drought, and caused citywide flooding and devastation. I’ll never forget the sight of Coast Guard helicopters performing water rescues in downtown. So, don’t ever hope for a tropical system to come your way. Ever.

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