How Climate Change Helps Drive Extreme Weather Events

Even if you don’t accept that human activity is altering the climate, the relationship between warmer oceans and extreme weather events is undeniable.

As Houston struggled in the aftermath of the record-breaking rainfall from Hurricane Harvey, and no fewer than three hurricanes simultaneously moved across the Atlantic basin, a reader asked if I could explain the role of climate change in the recent extreme weather events.

I want to connect the dots with arguments that aren’t really controversial.

First, is the climate changing? Almost everyone would agree that this is the case. What some would dispute is whether human activity is a significant contributor. I accept that it is, but I won’t attempt to make that case here. If you don’t accept that human activity is impacting the climate, I won’t be able to convince you in a short article here.

But let’s agree that the climate is changing. There are multiple lines of evidence that indicate that the earth is warming. One piece of evidence is that the surface temperature of the oceans is climbing. NOAA (National Oceanic and Atmospheric Administration) has determined that since 1880, the average global surface temperature of the ocean has increased by about 1 degree Fahrenheit (°F). (See their methodology here). Relative to the average temperature from 1971 to 2000, the surface temperature over the past five years has risen about 0.5°F.

These measurements aren’t controversial, as they have been confirmed by many different studies. But the temperature change varies depending on where it is measured. For example off the coast of Greenland, the surface temperature has actually declined by about 1°F. But according to data from NOAA and IPCC (Intergovernmental Panel on Climate Change), across much of the Atlantic and Pacific Oceans, the surface temperature has risen 1.5°F-2.0°F since 1900.

Again, you might dispute the reason, but there is really no disputing the measurements (other than perhaps the magnitude of the increase).

There are some effects we can expect from a warmer ocean surface. I will discuss two, that are based on physics. Warmer water will lead to greater evaporation, which should show up as higher humidity in the atmosphere. That has been observed, although as with the ocean surface temperature, some areas have seen humidity decline.

The net effect is that more water vapor in the air means more rainfall on average. This helps explain why Houston, for example, could experience three “500-year” flood events in three years. Since there’s more water in the atmosphere, the probability of these heavy rainfall events has increased. In other words, they aren’t really “500-year” floods anymore. Normal has shifted. Some areas are going to experience more rain and some less, but on average precipitation is on the rise.

The other impact of warmer ocean surfaces is stronger hurricanes. Hurricanes (as well as typhoons and cyclones elsewhere in the world) are massive heat engines that convert warm water into strong winds. Hurricanes are fueled by warm seawater, which is why you see them dissipate when they move over land, or into cooler ocean waters.

Thus, it would be expected that we would see stronger storms as a result of warmer ocean surfaces. That was certainly the case with Hurricane Irma, which set a record with top winds of 185 miles per hour (mph) for 37 hours.

While some are quick to blame climate change anytime there is an extreme weather event, these events have been taking place throughout history. It is wrong to blame any particular event on climate change, but the physics of why we can expect some of these events to become more extreme is well understood — even if some still reject that human activity is driving it.

18 thoughts on “How Climate Change Helps Drive Extreme Weather Events”

  1. We actually had a very much below average period of landfalling major US storms from 2006-2016. This was even after all the Rita/Katrina chatter from 10 years ago. So it is important to not make to much hay out of recent notable events and look at trends and statistics.

    Also, FWIW, it was the wind patterns that helped the recent storms rather than Atlantic ocean temperature. (granted those could be from GW also) Basically winds have a tendancy to rip apart hurricanes but the right weather pattern developed that allowed the storms to spin without getting ripped up.

  2. I’m so disappointed that RR has drank the climate change cool aid. Robert go to WUWT website and read it for a week, your just too smart.

    1. Which part of the argument do you dispute? That the climate is changing or that warmer oceans will create stronger storms and more rainfall?

  3. Brent’s link was interesting. The science cannot answer the question if GW spawned these hurricanes, but one can assume the science infers the storm is worse because of GW. Higher historical damage just an indication of more people living and building in hazardous areas.

    I read nothing of plant life or farm production shortfalls measures that prove GW impacts. Plant kingdom growth within our geological history proves otherwise. High heat and moisture a good thing for plant kingdom. Same for algae that loved prehistoric times. You know the plant kingdom that precipitated our fossil fuel supply.

    I do think it is improper to claim the phrase man made GW. First man makes nothing. Second, nature only can change the environment. So, we should label man’s activity as influencing climate. It may be bad or good. I will wager we have already experienced good within GW and that story goes untold. Who is to say what the best climate is or was. The science is in its’ infancy and up against a horribly complexity that can only improved within a extremely long time data set. Also, it’s extremely hard to obtain good data. At best they can raise a red flag or indicate a change. They can not foretell the future or extent of GW damage.

    It is good to pay attention and take action to minimize air pollution including CO2 and other GW gases. If it can be done within a reasonable budget and hopefully with benefits of our inventive nature. Fossil fuel is not particularly a cheap or clean energy source. Surely, we can improve. Nuclear has the wherewithal to do max good. Wind has some benefits, but not a particularly powerful power generator, nor can it be dispatch in accordance of need. A horrible situation. Solar is interesting, but anemic, expensive, and non dispatchable. Biofuel is very interesting given nature’s abundance of raw material and the developing chemistry to make processing cheaper. Grain ethanol is already more attractive in price, efficiency, and environmental benefit. Also, interesting that improvements in processing can be dialed up to make the fuel carbon negative. That would be interesting feat to accomplish. The more fuel you burn the less CO2 emitted.

    Also, hydrogen supply chain and fuel cell development might just solve wind and solar problems. Same with improving grid power and large power plant efficiency.

    So, in general if one keeps up with technological developments, we have little concern of GW other than to prevent the hype from giving free hand within government power expansion for nefarious desires.

  4. The Atlantic has been spawning hurricanes for thousands of years and we just went 12 years without a major hit. So you just joined the MSM blaming CC which is “Orwellian” for humans being the cause. We have hurricanes and we will always have them. I just hate that you gave credibility to the people who are using weather to take more of our freedoms.

  5. Did you actually read the post? Especially the last paragraph? I am not blaming the hurricane on climate change. My point, explained very clearly, is that 1). We know the oceans are getting warmer, and 2). We know that warmer oceans will lead to more rainfall and more intense storms.

  6. “even if some still reject that human activity is driving it”
    Someone with your stature has provided a quote that
    Jerry Browns of the world can use to help justify taxing carbon until we are all in the poor house. And the science is far from settled. Thank you for your interest of my feelings on this subject, to believe that humans could raise or lower the temperature of the earth is the height of arrogance.

  7. That’s an out of context, partial quote. I said that even if you don’t believe human activity is driving climate change, the climate is changing and we understand from physics what that means for rainfall and the intensity of hurricanes.

    This wasn’t an article arguing that humans are changing the climate. It was an article that said, “Even if you don’t accept that, here are things we do know.”

  8. Mr. Rapier let me say two things, 1. I have read you for several years now and will do so in the future. I greatly respect your view on the topics you have covered and have suggested to others many times to read your work. 2. Please consider that today Maria was the strongest hurricane to hit Purto Rico in 80 years. With billions less people and untold less tons of carbon in the air, why in gods name did it happen 80 years ago. Why can’t people accept it’s just weather and it’s going to happen.

    1. Did you ever wonder why we rarely have hurricanes in the winter? Or why they peak in late summer? It’s because of the water temperature. That has been rising, regardless of whether humans are causing it (my point). We know from physics what that does.

      Of course, we have always had big storms. The question is, are they becoming more extreme? As the water warms, that’s what we would expect. There will be more of these extreme weather events as a consequence of warmer waters — again regardless of why the waters are warmer.

  9. Ok, let’s look at this point. Since 2005 nothing much happened, sure hurricanes formed but nothing close to 2005 or 2017. I don’t have the information but I would be hard pressed to believe that the Atlantic and the Caribbean oceans temperatures during that period were much different than they are today. So why did we have years of such low activity. I understand your point that the energy source for the hurricanes are the btus in the water and logic dictates that the hurricanes have to bigger and more frequent if the oceans are warmer.
    Logic tells me that for all of those years something more important than ocean temps was in play. Lastly I believe that “people” are using this climate change issue as a means to an end that serves them and the cost to the public at large be damned.

    1. “Logic tells me that for all of those years something more important than ocean temps was in play.”

      There are definitely things in play that aren’t well understood. All I am doing here is saying “Here are some things that we do understand.” Beyond that is an extrapolation of the purpose of this article.

  10. Robert, I don’t know if it’s even worthwhile publishing articles like this, people are so determined to misunderstand them. As you’ve noted in the comments, some people just read “climate change” and “hurricanes” together, and leap to unwarranted conclusions without comprehending what you actually said. As I understand it, it’s even possible that global warming could reduce hurricane occurrence, as hurricanes needs calmer upper level winds to avoid decapitation by shear forces. But, undeniably, once a hurricane gets going its all about sea surface temperatures. More heat = bigger hurricane.

    1. Yes, there is absolutely a lot we don’t know and understand. You will never hear me say something like “the science is settled” because we always have more to learn. I understand what people mean by that phrase, but it is widely misunderstood. As long as models vary from reality, and as long as we still don’t understand some pieces of the picture, I would never say “the science is settled.”

  11. Mr. Rapier

    You sir are a gentleman and a scholar and I feel quite honored and humbled having this exchange with you. I wish you all the best ” Live long and prosper “

    1. I can’t see the interview from work, but that won’t impact the intensity of the storm, which is driven by the water the hurricane is over. That could impact the probability of a hurricane forming but should have no bearing on the strength of the hurricane.

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