The Climate in Emergency

A weekly blog on science, news, and ideas related to climate change


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Gone with the….

Wind has been in the news lately.

Cyclone Winston  became a named storm on February 10th and then spent 12 days blowing around the South Pacific–literally, the storm track curved back on itself and made a big loop, something I personally hadn’t known was possible. It crossed over Fiji as a Category 5 storm, killed 21 people, and literally leveled whole communities–a kind of destruction more typical of powerful tornadoes. At one point, the storm packed sustained winds of at least 186 mph. That’s the most powerful storm ever measured in the southern hemisphere.

Then, on February 23rd and 24th, a swarm of tornadoes swept through the United States, killing at least three and injuring many more. The storms (though not the tornadoes) actually passed over my area, giving us high, gusting winds and thunder. In February.

Of course, some kind of extreme weather probably occurs somewhere on the planet every day. It’s a big planet, after all. But these are both extreme extremes–Cyclone Winston was one of the most powerful tropical cyclones ever measured. And the tornado outbreak was in February. And they both relate to climate change–although, so do all other weather events, extreme or otherwise, since the climate changes on the just and unjust alike. Still, it’s interesting to look at the actual connections.

First, Winston. As I’ve written before, tropical cyclones with sustained winds of 75 mph or more are called different things in different ocean basins and different basins also have different storm seasons, and different storm behavior. In the North Atlantic, these storms are called Hurricanes. Winston was called a cyclone because it existed in the South Pacific where it is now late summer. So if it seems like we’ve heard about the “world’s most powerful storm” rather often recently, that’s in part due to the fact that we’ve had multiple basins turning up extraordinary storms, not multiple records being set and broken in just a few months. Still, we do seem to be seeing a lot of big storms lately.

As I’ve written before also, it is hard to tell for sure if tropical cyclones have been getting worse because we only have a few decades of quality data–and the way meteorologists study these storms vary from one ocean basin to another, too, which means that much of the data we do have cannot be pooled. We know that climate change should be making tropical cyclones stronger, more frequent, or possibly both, because the new climate involves warmer water and more humid air, both of which are what makes tropical cyclones happen–we just can’t actually see the changes yet because of the data problem.

But Winston was actually the result of multiple atmospheric cycles working together. Tom Yulsman write a clear and interesting article explaining these cycles. You can find his article here. To summarize, both global warming and El Niño were involved in the unusually warm water that fed the storm while an even shorter cycle, the Madden-Julian Oscillation, that changes over just weeks, made the atmosphere more stormy at just the right time. Day-to-day weather changes then steered the storm through its bizarre circular track and right over Fiji.

So the simple answer is that yes, while we don’t have the data to confirm it, we can be pretty sure that these record-breaking storms have some degree of extra edge due to climate change–and at the same time, other patterns also influence the situation.

Meanwhile, Cyclone Winston exemplifies another pattern–no matter how strong or weak a storm is, it’s going to be worse for impoverished people. Wealthy people can afford to rebuild and wealthy countries can afford to provide extensive aid. Many of those in Fiji can access neither wealth nor extensive aid–they are literally asking for help from the world. And because Fiji is very small and very far away from many of my readers’ countries, it’s all too easy to forget about them.  Please help if you can and spread the word.

As to tornadoes, again we have a serious problem with a lack of quality data. It’s hard to tell whether there are more tornadoes than there used to be when until recently there was no way to tell a tornado had happened unless somebody was there to see it. But recently some researchers have teased out a changing pattern. Apparently, the number of days per year that have tornadoes on average are stead or dropping, but the number of tornadoes per outbreak is going up. That is in keeping with the warmer, more humid air, which should make storms more powerful, and a simultaneous decrease in wind shear, also a result of global warming, which makes tornadoes less likely. So, fewer days when tornadoes can form, but on those few days, the storms are worse.

But February?

Tornado swarms in February are rare but hardly unheard of. But what some writers are saying–that the atmosphere is behaving “as though it were May“–is very striking. It’s an acknowledgement that this past week’s storm is part of a pattern that we usually don’t see and it is directly related to warmth. Specifically, the Gulf of Mexico grew unusually warm and did indeed create a kind of weather more typical of a warmer month. Given that the world is warming, these storms are a bad sign of things to come.

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Your Tuesday Update: Indonesia

For this update, I’m going to direct you to an article by George Mionbot about the forest fires in Indonesia.

In case you can’t see that link, here it is again, right HERE.

Basically, there are massive wildfires going on right now, burning through huge areas of forest that are home to critically endangered animals, including orangutans. The smoke from the fires is also causing major air quality problems in the region, to the extent that thousands of people, especially children, may die. And those fires are now a massive source of greenhouse gas emissions.

Forest fires are themselves not usually a big problem–forests that burn regularly adapt themselves to fire, and areas that burn are recolonized by organisms from areas that did not burn. The carbon dioxide emitted by the fire is taken up again as the forest grows back. But Indonesia’s forests have apparently been mismanaged for a very long time and that, combined with a serious El Niño-related drought, has allowed material to burn that otherwise would not have–releasing carbon dioxide that had been sequestered for a very long time and will not be easy to soak up again. Not to mention the fact that when habitat is already fragmented by logging and the palm oil industry, there might not be any left to spare to a forest fire So this isn’t a normal fire; it is a very serious situation which humans essentially caused and which is essentially being ignored (the story is being covered by big-name news agencies, such as NPR and the New York Times, it’s just not making the kind of headlines the scale of the problem deserves).

Read the article. And make some noise about the palm oil industry.


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Your Tuesday Update: ENSO

We are in an El Niño.

El Niño is one extreme of the El Niño Southern Oscillation, a large-scale climate pattern that is still difficult to predict. The ENSO cycle has a huge influence on which parts of the world get what kind of extreme weather–since extreme weather is also a feature of climate change, it makes sense to ask how the two interact, but the truth is we still don’t know.

I’ve written about ENSO before several times–in part because all last year they kept saying we were about to have an El Niño, but we never quite got there. The characteristic warm water in the Pacific was there, but not the accompanying  air patterns. It was very odd. And it makes me wonder–since part of what defines an El Niño is warm water, and since climate change is unquestionably warming the seas, might we start seeing partial El Niño events, in which climate change mimics some aspects of the ENSO cycle? Is that what happened last year?

Just a thought.


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They Make Floods Bigger, in Texas

On the PBS NewsHour yesterday, during the wrap-up, stuck in without comment between other tidbits was the following:

The governor of Texas declared disasters in two dozen counties today, after a weekend of catastrophic flooding and tornadoes. And the severe weather continued early today, as a storm blasted a Mexican city just across the Texas border….Central Texas bore the brunt, with creeks and rivers rapidly swelling, sweeping cars away. At least a dozen people were missing after flash flooding sent the Blanco River rising 26 feet in an hour. Across Texas, hundreds of homes were destroyed, and nearly 2,000 people were forced to move to higher ground….In India, there was no break in extreme heat that’s killed more than 500 people in recent weeks. Temperatures in one northern state reached 116 degrees on Sunday. People suffering from dehydration inundated hospitals that were battling power outages. And streets in several major cities were abandoned as people sought out shade.

Um, what? A river rose 26 feet in an hour?

The video that flashed by behind Judy Woodruff’s words included a highway bridge that was just completely gone. An emergency vehicle, its light flashing, itself became a victim, tumbling over and over in the rushing, brown water. There was no mention as to whether there was anyone in the vehicle at the time. In India, unhappy women in saris huddled in the shade and children say on cots and cried.

Ms. Woodruff provided no commentary or context for any of this, no hint of whether these stories comprise an ordinary rash of bad luck or something truly bizarre. How hot does it normally get in India in May? How often do bridges wash out in Texas? I do not mean to pick on Ms. Woodruff or any of her colleagues–I call out the PBS NewsHour on its lack of climate coverage often because I watch the show often. Overall, I very much like it. But part of the job of a journalist is to give the audience some kind of context.

Of course, my first thought, watching the news, was that these events are signs of climate change. I’m not alone in that reaction–an Internet search on “Texas flooding and climate change” yields lots of recently posted results. It’s true that because anthropogenic climate change is happening, all weather plays out against its reality, but this particular group of events seems notably freakish, a reminder that we really are living with a new normal. Are we? Intellectual honesty demands that we make sure we’re not reacting simply to variations in news coverage–perhaps disasters on this scale are actually fairly common, but this is a slow news weeks or something?

I have not found a precise answer to that question. I’ve been focusing on the floods–since I’m in America, it is easier for me to research an American disaster–and I have found some comparrisons and some numbers.

Houston, one of the cities affected by the recent flooding (and still mostly under water) gets an average of 4.45 inches of rain in May. Yesterday (Monday) parts of the city got about 10 inches–that’s over twice the month’s rainfall in a single day, and Monday was hardly the only day of rain–parts of Texas and Oklahoma have been getting unusually heavy rain for months now. Austin has had its wettest May since 1921. The Governor has called it the worst flood in that part of the state in its history, and while he may or may not be accurate, the extreme language is striking–the floods follow hard on the heels of the state’s worst-ever drought (parts of Texas are still in a mild drought now, so great was the deficit).

So, clearly these events are unusual. But are we talking “Cat 5 hurricane in Florida” unusual, or are these recent storms are the equivalent of a Category 5 hurricane in Wyoming?

I asked a friend who lives just outside of Houston–who, by the way, currently has no electricity–and she said the flooding reminds her very much of Hurricane Allison, in 2001. She says that flooding in her area is just something she and her neighbors know to watch out for, since their area is vulnerable to hurricanes. She seems shocked the way one always is by frightening, destructive things, but what she’s seeing is not outside the  realm of what she’s seen before (although it’s possible she doesn’t know how bad it really is, yet).  She also made an important point:

Floods are not just about how fast water comes out of the sky, but also how quickly water can leave again.

Houston is still growing, still being further built up. The area is losing its permeable surface area and with it the capacity to absorb rainwater. Meanwhile, sea level rise also makes it harder for rainwater to get out of the way–as my friend put it, the water has to have some place to go. An historically ordinary downpour, therefore, could still cause an extraordinarily severe flood, at least in Houston. I am not sure how such issues apply to the other flooded areas. So the issue is more complex than climate.

In any case, more droughts and more flooding is exactly what is predicted for climate change in Texas.

We know that a warmer atmosphere drives faster evaporation, which means both deeper droughts and more moisture-laden clouds. More extreme weather is therefore predicted in a general way all over, and Texas specifically is supposed to get more floods because of the moister air (the severity of the heaviest rainfalls on the Plains has gone up by 16% since the 1958) and because of changes in the behavior of hurricanes.  We also know this is an El Niño year, a weather pattern that tends to direct wet weather to the southern half of the US, but it is possible that global warming exacerbates El Niño, no one knows for sure. So, freaky or not, the current weather in Texas and Oklahoma is entirely consistent with the reality of climate change.

Are these storms really a freakishly new thing that could not have happened without climate change? I have not been able to find out–someone will have to do a statistical analysis of data I don’t have access to to answer that question. But, if they aren’t, that’s not really comforting.

If this isn’t the new and destructive normal yet, then we can expect both droughts and floods in Texas to get worse.

 

 


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Western Pacific Typhoons

Japan can’t seem to catch a break this year.

Aside from the eruption of Mount Ontake (which was quite a disaster, but tangential to this blog), the country has had a serious problem with weather, especially flooding. Three typhoons have made landfall on the islands so far (Neoguri, Halong, and Phanfone), plus, Tropical Storm Man-yi raked the length of Japan in September, dropping almost twenty inches of rain within two days. At least one non-tropical rainstorm in August caused flooding and deadly mudslides as well. An Internet search for “unprecedented flooding Japan 2014” yields multiple results not all of them from the same storm. 

Japan is large enough that these storms have not all hit the same places, but still, it must be very difficult to be Japanese this year.

Another storm is on the way now, the startlingly monstrous Vongfong. There is some hope that it will weaken before hitting Japan itself, but it is a super typhoon and is one of the most powerful storms on record–ever. It is being compared to last year’s Typhoon Haiyan, the very existence of which convinced many that something has gone really, really wrong with Earth’s atmosphere. Well, now here’s another one.

To be clear, a typhoon is the same thing as a hurricane; different ocean basics use different names for the same type of storm. The collective term for any storm with this kind of structure is ” tropical cyclone.” A tropical cyclone that has sustained maximum wind speeds of 75 MPH or more is a hurricane, a typhoon, or a cyclone, depending on where in the world it is. Tropical depressions and tropical storms are weaker versions of the same thing. A super typhoon is the equivalent of a class 4 or 5 hurricane.

I have found little to no discussion of Japan’s troubles in general, or Super Typhoon Vongfong specifically, in terms of climate change so far. Perhaps the problem is that I can’t read Japanese and so am probably missing the vast bulk of coverage on these storms. I expect that if Vongfong causes a major disaster we may hear more about it here in the English-speaking world.

In the meantime, I am curious–when such discussions do get going, will they have a basis in fact?

Each storm basin produces slightly different storm behavior, with different storm seasons and different numbers of storms being typical per season. The Northwest Pacific basin is the most active in the world; it runs all year, though there is typically a lull over the winter, and its storms are often more powerful than those in the Atlantic. So a season that looks vicious to a writer based in the United States might be normal for Japan. So, is this an unusually powerful typhoon season?

Based on 1981-2010 data, the NW Pacific can produce anywhere from 14 to 39 storms of tropical storm strength or more, with an average of 26. Of these, anywhere from 5 to 26 are typhoons, the average being 16.5. Since 1960, the number of super typhoons per year varies from 1 to 11.

Getting a reliable list of the actual storms in this season is difficult, probably because English sources focus on the two basins that can threaten the United States and the NW Pacific cannot. By comparing several different blogs and news sites–not all of which agree with each other–I conclude that Vongfong is the basin’s ninth typhoon and its sixth super typhoon. These numbers are right in the middle of the typical range for the last several decades, but since the year still has three more months to run, this does look to be a busier than average year–but not an extraordinary one.

I am not a climatologist, so I could easily be contradicted here, but it looks like the only extraordinary thing this year–so far–is Vongfong. That might be enough. And of course, climate change does not cease to play a role in the weather when the weather is average or even calm; global warming is not an event but an element within all events. And even if the frequency of this year’s storms is not unusual, storm surges and total rainfall are higher than they would be without global warming. Recently I made a rough tally of the people who die of global warming? Get ready to add a few more when Vongfong rolls in.

Part of the reason I wanted to write about the Pacific storm season this week is simply that I know most of my readership is American, and American media (somewhat understandably) focuses on American news. I wanted to post a reminder that extreme weather still happens even when it isn’t happening here (though, of course, parts of the US are suffering from extreme weather as well).

But the other reason is that I’ve been watching the Pacific, expecting an extreme season, just as I’d been expecting a mild Atlantic season. This was supposed to be an El Niño year. As I said this spring:

El Niño refers to an unusual weakening of the trade winds, which causes warming of certain parts of the Pacific ocean. The name means “the Child,” referring to the Christ Child, because of the bad fishing the warm water causes off of Peru around Christmas during El Niño years. The pattern radically changes the weather across much of the globe. For example, El Niños partially suppress Atlantic hurricane activity but increase hurricane formation in the Pacific. A stronger trade winds and a cooling of the Pacific is called La Niña (“the Girl,” because it is the opposite of “the Boy”) and likewise alters worldwide weather. The Pacific moves between these two extremes every three to seven years for reasons no one really knows. The cycle is called ENSO, for El Niño Southern Oscillation.

When I wrote that, signs were good (or bad, depending on your perspective) that an El Niño was going to develop. It has not not happened yet, though it is still possible. Apparently, the Pacific waters have warmed, but other aspects of the El Niño pattern have not developed. I don’t know whether this year’s quiet Atlantic hurricane season is related to this almost-Niño or not. The busier than average Pacific season probably is, since the Pacific has been warmer than usual, and tropical cyclones feed on warm water.

An interesting question is whether the Atlantic is also warmer than usual? It might well be, if the relative lack of hurricanes is due to increased wind-shear (as it would be in an El Niño year). That is, warm water can cause increased storm activity, but decreased storm activity does not, all by itself, mean the water is cool.

The thing is that nobody knows what drives the ENSO, and so nobody knows its real relationship to climate change. It’s a reasonable guess that we could be in for more frequent or more severe El Niños, since both involve warming water, but we can’t be sure. Something else besides warm water might be necessary, and without that something else, more frequent El Niños might not happen.

I’m wondering if perhaps this is what the future looks like? Pools of warm water forming in the Pacific (and possibly elsewhere), causing some of the effects associated with El Niño, but not all of them? If so, Asia had better watch out.

If anyone has further insight on this, please drop me a line.