Thursday, February 15, 2018

The Global Temperature Records

Every January, the global mean temperatures for the previous year are announced.  Four institutions worldwide maintain running temperature records, and sometimes they draw slightly different conclusions.  That was true in 2017, as one institution called it the second warmest year on record while the other three called it the third.  (Last year, I had predicted it would be the third warmest year.)  So who are these four institutions, and why don’t their records produce uniform agreement?

Two of the four institutions that maintain temperature records, NASA’s Goddard Institute for Space Studies (GISS) in New York and the National Oceanographic and Atmospheric Administration (NOAA, headquartered in Silver Spring, Maryland) are U. S. government agencies.  The other two agencies are the British Meteorological Office and the Japan Meteorological Agency.  These records, based primarily on thermometer readings from many weather stations and ships worldwide, enable analysis of local temperature changes over time as well as changes in the global mean temperature.  When talking about global warming in general terms, though, the annual mean variations in global mean temperature are usually presented.  NASA GISS reported a global mean temperature anomaly of 0.90ºC (1.62ºF) relative to the mean 1951-1980 temperature, their second largest anomaly behind 2016.  NOAA had a result of 0.82ºC, the Met Office 0.70ºC, and Japan 0.73ºC, when normalized to their 1951-1980 means.  These three agencies had 2017 third in temperature, between 2016 and 2015.  The reason these are different has to do with the methodologies that the four organizations use.  A detailed explanation of the different methodologies can be found here. I will summarize the NASA GISS methodology by saying that it is more aggressive in counting ocean temperatures in the northern part of the world, where direct measurements are scarce.  The rationale behind this approach is that this part of the world has been the most sensitive to the influence of global warming so far.  This also explains why the GISS record tends to have higher numbers for the global mean temperatures than the other records do.

You might also be wondering why temperatures are expressed in terms of an anomaly, rather than a specific value for the temperature.  The reason for that is that it is easier to measure the change in temperature at a specific location, after accounting for factors like the urban heat island effect or proximity to ship engines that might skew the specific value of the temperature, than it is to define the specific value of temperature at a site unambiguously over time.  Furthermore, in regions where coverage is sparse, the average change in measured temperature is more likely to accurately represent that of the full region than the average measured temperature itself.
Figure 1

Figure 1 shows the plot, from 1890 to the present, of global mean temperature anomalies as determined by all four agencies normalized to their mean values between 1951 and 1980.  (GISS is black, NOAA is red, the Met Office is green, and Japan is blue.)  While they don’t agree on the exact numbers, they certainly do reflect the variations in temperature very similarly, in terms of both year-to-year shifts and the underlying long-term trend.

Regardless of which data set you look at, a very important conclusion can be drawn.  As 2017 was not significantly influenced by an El Niño event like 2015 and 2016 were, it is the warmest year on record without such an influence.  As I’ve discussed in a previous blog entry, the El Niño/La Niña cycle is the primary driver of natural variability in the temperature record.  So keeping natural variability in mind, the sharp short-term surge in global mean temperatures that became noticeable in 2014 is continuing.

Tuesday, January 16, 2018

When Other Things Take Precedence, Again

Much like when I posted about the tension in Charlottesville back in August, I want to discuss something here that isn’t directly about energy or global warming, but did dominate the news throughoutt this past fall and ultimately affected a class I taught in the fall semester.  I am talking about the series of sexual harassment scandals that started with movie producer Harvey Weinstein and went on to adversely affect the careers of a number of people in entertainment and politics.  Up to this point, I have mostly refrained from talking about this particular issue.  I could sense from the beginning that it would wind up affecting people that have done things that I have admired, and I wanted to take some time to think about it before weighing in.  I think it is worth bringing it up in this blog because the most prominent political figure affected by this scandal, Minnesota senator Al Franken, has been a very eloquent speaker on the issue of global warming.  Franken, of course, resigned his position after a very damning photograph came out showing him engaged in a thoughtless prank directed at a sleeping female comedian, followed by a number of other women accusing him of inappropriate behavior.

I know that plenty of people feel that Franken has been denied his right to due process, but I want to start by saying that I don't believe this is ultimately about whether Franken is innocent (he's not) or whether he has committed any action that is irredeemably bad or criminal (he hasn’t).  The issue to me is whether or not Franken has lost the authority to speak effectively as a statesman on the issues of our time.  As this is a blog about global warming, I want to present as a case in point a discussion Franken had on the Senate floor this past June with the United States Secretary of Energy, Rick Perry.

I teach a class on Energy and the Environment at St. Joseph's College in Patchogue, New York.  When I saw this clip I had every intention of showing it to my class at the end of the fall semester, when I discuss how to respond to skeptical arguments against the idea that global warming is happening and human activity is responsible for it.  The clip demonstrates very well that it's important to understand how the scientific method works, and that you don't need to be a scientist to be able to do that.  (Keep in mind that before he became a senator, Al Franken made a living writing jokes for Saturday Night Live.)  But as you can probably guess, I couldn't show this to my students.  Franken’s behavior in other regards had become too much of a distraction, and presenting him as a champion of good sense no longer seemed prudent.  I was angry and disappointed, but it was not the fault of Franken’s political opponents, or his female Democratic colleagues in the Senate who collectively asked him to resign, that this happened.  And it was certainly not the fault of the women who have spoken out about Franken’s behavior towards them.  Regardless of how well he may have spoken on a variety of different issues, Al Franken lost his voice.  He did not have it taken away from him.

But the important detail that I had wanted to emphasize from this exchange was not that Franken possessed any special, irreplaceable gift for speaking about global warming or other issues.  In fact, the opposite is true.  For a person whose education has lasted at least as far as high school, it takes as much time to understand how the scientific method works as Franken spent explaining it to Secretary Perry.  This isn’t difficult.  Scientists critically evaluate each other’s work all the time, just as they have been doing for centuries.  What holds up to scrutiny is preserved, and what doesn’t is disregarded.  The system isn’t necessarily perfect, but Perry recommended in this clip that the best response to research that has survived decades of scientific scrutiny and led to an uncomfortable conclusion is not to act on the uncomfortable conclusion, but to subject it to more scrutiny (and in a highly subjective setting at that).  No, Secretary Perry, there is nothing whatsoever that is wrong with being a skeptic.  But truly being skeptical requires not only demanding evidence and critically evaluating it, but accepting when the evidence has indeed withstood the scrutiny.  The scientific process is based on healthy skepticism, and good science endures because of it.  This is something that everybody can understand well enough to defend it.

As the smoke starts to clear from this ordeal, there are things to hope for.  I do hope that Al Franken gets the opportunity to redeem himself in the not-too-distant future.  I also hope all people can learn to speak as well in defense of the scientific method, and the difficult conclusions it sometimes leads to, as Franken did in his exchange with Rick Perry.  It's necessary, and it’s actually not very hard.

Tuesday, January 9, 2018

Last Year's Predictions

With 2017 officially over, I thought I would look back at a couple of predictions I made regarding our current administration’s energy policy and the state of our climate, and see how they played out.  Prediction is an important part not only of science but of analysis in general.  If the insights are solid, they should hold up not only to scrutiny at the time they are made but also to the tests that time puts them through.  Sometimes the unexpected still happens, of course, in which case you re-evaluate your previous opinions and beliefs and learn from what you got wrong.

I’ll start with a Facebook post I made the week after the 2016 election, based on a conversation I had with a colleague:

“One of the physics professors at Adelphi asked me how I thought the election would affect our energy production (and subsequently our CO2 emissions). I have a few thoughts that I figured I'd share.

1. For economic reasons, the coal industry has shrunk over the last decade. For economic reasons, the coal industry will not have a resurgence (all statements to the contrary by the President-elect notwithstanding).

2. The natural gas industry will meet with a friendly reception. Not getting into the debate on fracking for the time being (like it or not, there will be a lot of it), methane burns cleaner than other fossil fuels but it causes a significant climate impact when released to the air directly. There is plenty of scientific data at this point to suggest that the EPA's current methane emissions estimates -- and keep in mind, this is Obama's EPA -- are too low by close to a factor of two. This is a problem for all sources of methane, including the gas industry. A big issue that needs to be addressed is the combination of a surge in production with some seriously old infrastructure. (I explained it to my students this way: More than half the existing gas pipelines are older than I am, and as much as I hate to admit it, I'm not that young anymore.) Trump says he's all about infrastructure. We'll see.

3. Renewables will get a less friendly reception, but the good news is that they are in a position to survive that -- utility-scale solar is already cost-competitive with coal and gas. And if storage batteries can be made cheaply, they may even thrive.

4. Where renewables will face the most trouble is government-funded research. In September, I had the great pleasure of taking my class to Brookhaven Laboratory to see the solar-related projects there. I worry that projects like that are very vulnerable now.

5. The status quo will hold where CO2 emissions are concerned. While basic reality dictates that we cut our emissions with a sense of urgency, and that won't happen, CO2 emissions have actually dropped a little in recent years and I don't see them going back up.”

Regarding the first point, the economic health of the coal industry has not improved any in the past year.   In fact, according to Lazard's most recent analysis of the levelized cost of energy, the cost of coal has remained steady over the past year while the costs of natural gas, utility-scale solar, and wind have all dropped.  So coal’s foothold in the energy sector is indeed getting more and more tenuous.

I was a bit off on the second point, however.  I would have thought that anybody interested in defending fossil fuels would sing the praises of natural gas very loudly, given that it is cleaner than coal (it emits about half as much carbon dioxide per unit of energy released) and that it is presently cheaper than coal with a widening gap in price between the two.  But that is not what happened.  Instead, a Notion of Proposed Rulemaking submitted by the Department of Energy in September suggested offering tax breaks to power plants that could maintain 90 days worth of fuel on-site.  This proposal attempted to tilt the energy market away from natural gas plants, whose fuel supplies are generally piped in as needed, and towards coal and nuclear plants.  Just yesterday, though, the Federal Energy Regulatory Commission rejected the proposal; it makes bad economic sense, in addition to making terrible environmental sense.  Lobbying for the coal industry does score political points in states like Pennsylvania and Ohio that were critical to Trump’s electoral victory in 2016, however, so at this point I would expect the President to make similar attempts to prop up coal in the near future.  Moving ahead to the last sentence in my second point, Trump has yet to make a serious move on infrastructure.  So I guess we'll still see.

The third point was pretty accurate on the whole.  Utility-scale scale solar and wind remain competitive, and their costs continue to drop.  The price of utility-scale solar with battery storage dropped substantially, from $92 per megawatt-hour to $82 per megawatt hour.  Ultimately the battery storage is necessary for renewables to overcome the obstacle of intermittent generation (meaning you don't get electricity from a solar panel when there is no sun or from a windmill when there is no wind).  A fully clean energy sector simply cannot happen without it.  There are no obvious policy obstacles standing in the way of renewables right now; in fact, the only real obstacle is the price of natural gas.

Thankfully, there has been no major push to cut funding for renewables-related research to date.  I do still worry, though, that those projects are vulnerable.

I should have specified in my fifth point whether I was talking about global emissions of carbon dioxide, or specifically American emissions.  According to the recent estimates of the Global Carbon Project, American emissions in 2017 dropped slightly by approximately -0.4%.  Global carbon dioxide emissions have unfortunately gone up, however, primarily due to an uptick in the Chinese economy.  This underscores the need for more urgent and aggressive action across the board in reducing carbon emissions.  It’s pretty clear that our current administration won’t lead that charge, but some states are stepping in to fill the void.

The next prediction I would like to talk about comes from the blog post I made titled Breaking the “Icy Silence.”  The post discusses the drop in temperatures in the later part of 2016 that corresponded with the end of the very strong El Niño event that contributed to three straight years of record warmth.

“As for the drop, the 2015-2016 El Niño has certainly ended, but the present state is closer to neutral than to a full-blown La Niña event.  This suggests that ENSO-neutral conditions presently result in a temperature anomaly at, or maybe a little bit above, 0.80ºC.  Were this state of general neutrality to continue for the rest of the year, 2017 would wind up comfortably being the third warmest on record, but that ultimately depends on whether or not a strong La Niña ultimately happens.”

A strong La Niña event did not materialize early in 2017.  Instead a weak El Niño emerged in late spring, making it look for a while that 2017 might wind up being the second warmest year on record.  But the El Niño quickly dissipated and now it looks like the La Niña is finally happening.  As of November (the December data needs to be processed and won’t be available until the middle of the month), 2017 had a mean temperature anomaly of approximately 0.84ºC relative to the twentieth century mean— comfortably the third highest on record.   NOAA is predicting a weak to moderate La Niña event that will last through the winter.  I’m going to predict that this will cool the air off enough to make 2018 the fourth warmest year on record when all is said and done.  We’ll see how that prediction looks this time next year.

Tuesday, January 2, 2018

December's Foggy Freeze

I wanted to talk today about the recent weather here on Long Island and in the northeastern United States as a whole.  The area is experiencing an extended cold spell, with the current forecast calling for a fairly significant weather event later on in the week followed by even colder temperatures.  I will wait until the end of this month to see how January plays out, but I think it's worth discussing the cold December we've had in the context of our weather history over the last half-century.

I looked at temperature records for the month of December going back to 1965 from the weather station located at LaGuardia Airport, using the Weather Underground site.  The mean temperature for December 2017 was 36°F.  How does that compare to Decembers of previous years?  The graph below plots the monthly mean December temperatures since 1965, with the most recent data point being December 2017.  As you can see, this past December was indeed cool compared to recent Decembers.  It wasn't the coldest December on record, though; nor would it have been that abnormal relative to the early part of the data set.   The decadal means for December temperatures were 36.6ºF from 1965-1969, 37.3ºF for the seventies, and 36.4ºF for the eighties.  In other words, it wasn’t that long ago when this December would have been considered very close to average.  Temperatures have risen noticeably since then, however.  The decadal mean December temperature was 39.9ºF in the nineties and 38.6ºF in the 2000s.  This decade, even given this past month, has seen a mean December temperature of 41.1ºF.  It is also worth pointing out that December 2015, with an average temperature of 51°F, was far more anomalously high than 2017 was anomalously low.  (My vegetable garden was still going strong that December, and I even had broccoli growing into the new year.)

So I think a little perspective is required when discussing the current cold spell.  Weather happens, and sometimes things get cold in the winter regardless of the overall trends in temperature.

Friday, August 18, 2017

When Other Things Take Precedence

First of all, I would like to apologize for taking so long to publish another blog entry.  Between teaching my summer physics class, traveling to Florida for a week, and trying to get our current house sold so we can move into a new house, I've been rather busy.  I was all set to post a review of Al Gore's latest movie An Inconvenient Sequel, but something happened this past weekend that made global warming actually seem temporarily insignificant, even to somebody who has a blog devoted to global warming.  Of course I'm talking about the events in Charlottesville, Virginia, where a series of marches that included people carrying Nazi flags and saluting Hitler led to the death of a counter-demonstrator who was standing against prejudice and bigotry.  To make a bad situation much, much worse, our President utterly failed to quickly denounce and distance himself from the groups leading the demonstrations, and in fact portrayed both sides as equivalently antagonistic. 

I started this blog to combat ignorance on a subject I know quite a bit about and care very deeply about.  Extreme ignorance takes on many forms, but whether it leads to direct acts of violence against people who are different or it compromises the long-term health of our planet, it is very dangerous.  I used to believe that ignorance would expose itself; people would simply see it for what it is, and our society as a whole has experienced too much too ever again let it gain a meaningful foothold.  I can remember when I was a graduate student at the University of Delaware in 1993, and the Ku Klux Klan were holding a rally in the heart of the town of Newark.  A lot of people attended the counter-demonstration, which significantly outnumbered the Klan rally, but a friend and I instead opted to attend an alternative rally emphasizing harmony and diversity.  Creating something positive out of a negative situation certainly has its merits, but circumstances have changed since then and made me question whether that was really the prudent thing to do.  Ignorance and hatred can spread just as easily as true knowledge and empathy can, and combating the people who propagate these things requires reaching out to people with a greater and more relentless passion.  The stakes right now are very high.  In the case of hatred and bigotry, neo-Nazis salute Trump along with Hitler and feel emboldened by the results of the 2016 election.  In the case of climate change, people who refuse to acknowledge the scientific reality of global warming now dictate energy and environmental policy from the executive and legislative branches of our government.

So what, then, can we do?  For one thing, we need to call out ignorance whenever we see it, regardless of the form that it takes.  Yes, you can certainly argue that those who are ignorant of our history are doomed to repeat it.  You can also argue that those who consider Confederate soldiers to be heroes worthy of monuments are ignorant of our history.  Similarly, you can argue that people who insist that a case remains for reasonable doubt on climate change are ignorant of the decades of research that have led scientists to draw a very different conclusion.

I also believe that it is very important to not give in to our most angry and violent impulses as we resist hate and ignorance.  You don’t need to be Christian to see the disarming strength in loving your enemies, blessing them that curse you, doing good to them that hate you, and praying for them that spitefully use you.  And to quote Martin Luther King, the greatest enemy of hate and ignorance that this country has ever produced: “the nonviolent resister does not seek to humiliate or defeat the opponent but to win his friendship and understanding.”  The goal is not to defeat bad or misguided people, but to defeat bad, harmful, ignorant ideas and make all of us better people in the process.  Tell the truth.  Love, and include.  Be calm and respectful, but above all, be persistent and undaunted.

We’ll talk further soon.

Monday, June 5, 2017

Going Through Withdrawal

Last Thursday (June 1), President Donald Trump announced that he was withdrawing the United States from the Paris Agreement, a global co-operative effort to reduce the emissions of greenhouse gases in the hope of limiting global warming and reducing its effects.  He also announced that he was withdrawing from the Green Climate Fund, a United Nations effort to help the developing world build up its energy infrastructure without emitting more greenhouse gases, on the grounds that it was costing the United States “a vast fortune.”  The United States now joins Syria and Nicaragua as the only countries in the world not participating in the Agreement.  Nicaragua felt that the accord’s voluntary agreements did not go far enough, and the Syrian government’s status as an international outcast made it hard for representatives to participate in the talks.  The announcement was disappointing from my perspective as a climate scientist, to be sure, but it was not surprising.  Based on his statements in the campaign and his Executive Order on energy policy, it is clear which types of energy Trump supports and which ones he doesn’t.  Advocating for serious action to combat global warming is simply not consistent with his priorities. 

There isn't too much that needs to be said about the President’s horribly myopic decision.  You can find good point-by-point fact checks here and here, for example, so I don’t need to repeat that.  But as I mentioned in my post about the Executive Order, anybody knowledgeable about jobs in the American energy sector knows that Trump’s plans won’t actually promote job growth.  And anybody who knows the present cost of different types of energy knows that withdrawing has nothing to do with cheap energy, either.  Nor does it erase a prohibitive expense to American taxpayers.  The Paris Agreement itself did not require any binding financial commitments.  Such commitments would have required President Obama to bring the accord to the Senate for a ratification vote; given the Republican majority in the Senate, the vote would not have passed.  Obama voluntarily pledged three billion dollars, or ten dollars per citizen, to The Green Climate Fund.  As the Fund enables developing countries to build up energy infrastructure in places that don’t currently have any by using clean, renewable sources, I don't see why this cost is unreasonable.  It benefits everybody. 

What is clear is that President Trump believes that the best way to deal with the energy requirements of the 21st century is to stick with what worked in the 20th century.  Forget that cleaner energy sources than coal, and not just natural gas, are now cheaper.  Forget also that the entire rest of the world (except for Syria, whose people ironically have likely suffered far more than any other country to date from the effects of global warming) remains firmly committed to developing these energy resources further, regardless of what our President says or does.  Present economics dictates that Trump’s approach is counterproductive, and science indicates that it will do significant environmental harm.  He is essentially mortgaging the status of the United States as a leader in the the world, and the health of our planet as a whole, on obsolescent technology.

None of this should be taken as a cause for despair, however.  For one thing, the Paris Agreement was written so that withdrawing from it will take time.  Article 28 of the Accord states “At any time after three years from the date on which this Agreement has entered into force for a Party, that Party may withdraw from this Agreement by giving written notification to the Depositary.  Any such withdrawal shall take effect upon expiry of one year from the date of receipt by the Depositary of the notification of withdrawal, or on such later date as may be specified in the notification of withdrawal.”  The Accord can be withdrawn from more rapidly if Trump also withdraws the United States from the United Nations Framework Convention on Climate Change.  The Convention was entered into by President George H. W. Bush in 1992, and Democratic and Republican presidents alike have willingly participated.  Abandoning it would cement the United States as a rogue nation in the eyes of the rest of the world, and I can’t fathom that even Trump would find such a move prudent.  So barring that, the earliest date that the withdrawal can officially take effect is November 4, 2020 — the day after the next Presidential election.  A lot can happen in the meantime. 

Also, states and cities are taking the situation into their own hands.  In the wake of the withdrawal announcement, the states of New York, California, and Washington formed the U. S. Climate Alliance to maintain their part of American compliance with the Paris Agreement.  The best response to this, ultimately, is action at the statewide and local level, and this appears to be happening.  Action to combat global warming does not have to start at the top.  Right now, that is a very good thing.

Friday, May 5, 2017

The March for Science

photo by Donna Castagna-Gianelli

Saturday April 22, Earth Day, marked the global March for Science.  Scientists and non-scientists alike participated in the march in over 600 different locations around the world.  The reasons for marching were as diverse as the people participating.  For me, a college physics professor with a PhD in atmospheric science who spent sixteen years at one of the world’s major centers for climate research, it came down to the fact that we need to talk.  In a country where people with resources to spare and a vested interest in keeping people confused can send a horribly misleading book to every science teacher, we need to talk.  In a country where a series of regulations that honestly didn’t go far enough to protect our fragile planet can be undone with one stroke of a Presidential pen, we need to talk.  In a country and world where scientists can receive death threats for drawing the only conclusion the data allowed them to draw, we need to talk.  The discussion needs to be respectful and rational, of course, but scientists need to start and maintain an open dialogue with the public at large.  My fellow scientists and I cannot simply take it for granted that the results of our efforts will be accepted, understood, appreciated, and acted upon if needed.

 photo by Donna Castagna-Gianelli

I went to the march in New York City, with my wife and daughter.  From the onset, it was clear that this demonstration was different than most of the ones I’ve gone to in the past.  It wasn’t loud and angry, to be sure (notwithstanding a cascade of boos as we marched past Trump Tower).  In fact it was actually very friendly, with a tone akin more to a family gathering than to an angry protest.  We met scientists who’ve traveled to Antarctica to study the behavior of penguins.  We also met artists who made striking unicorn costumes, in the hope of raising awareness to the danger that some real creatures may become mythical in the not too distant future.

photo by Donna Castagna-Gianelli

People with a lot of experience at demonstrations might have found the atmosphere to be too polite, but it really wasn’t a bad thing.  More than anything, the march was a call for respect.  Scientists often work long hours for pay that can best be described as adequate, and the more momentum a research project has, the longer the hours become.  The results of these efforts include all the medical advances and other technology we now enjoy.  They also include greatly enhanced knowledge about the workings of the universe, including this little world on which we live.  Some of the things we’ve found out about our world are genuinely disturbing, though, and the interest of our elected government in dealing with the issue has declined even as the situation has become clearer and more urgent.

 I got my copy in my mailbox at Hofstra.  Did you get yours?

If a change in how the public views science and scientists is necessary and long overdue, scientists need to be more proactive in reaching out to the public about their work and what it means.   I felt that the March for Science was a good launching point.  It sent a simple message that we’re here, we’re human, and we’re concerned.  And above all, we need to talk.  Then, we need to keep talking.

photo by Donna Castagna-Gianelli