Paleo trash and unfrozen cavemen

Temperatures in NYC have finally risen persistently above freezing, and the ice and snow are starting to melt. In NYC one of the consequences of this is that all the garbage that was buried by the snow comes to the surface. The streets haven’t really been cleaned in weeks to months, and they are a mess.

It reminds me a bit of other things revealed by melting ice. Like Captain America in the movie… or, ok, if we want to be more real life-based, like Oetzi, the “iceman”, found in 1991 in the Alps between Austria and Italy. He was frozen 5000 years ago, and then unfrozen as the glacier he was in melted due to whatever combination of natural climate variability and anthropogenic warming.

So now today, we have scenes like this:

paleo trash march 2015

A little less scientifically important than Oetzi, but still, recent history (of a New York City sidewalk) preserved in ice and then revealed.

Of course, the most important artistic comment on this particular phenomenon is this.


US-China climate deal

I have an op-ed piece on CNN today about the new climate agreement between the US and China. The full piece is here, and the first three paragraphs below.

The agreement between President Obama and President Xi of China to reduce greenhouse gas emissions is the most important advance in the several decades-long history of international climate negotiations. It has been greeted with rage by those in Congress whose positions on the science are denialist or evasive (“I am not a scientist”). Their criticisms are specious and predictable.

But while most climate scientists I know are still sharing a period of joy following its announcement, some substantive criticisms of the agreement have also been raised. I want to address two of them here.

One is that the agreement doesn’t do enough to solve the problem of global warming. The other is that it doesn’t promise anything that wasn’t likely to happen anyway. Both of these criticisms have some truth, but neither diminishes the importance of what Presidents Obama and Xi have achieved.

Continue to full piece…

Climate Services: Two conferences on two continents

I spent this past week in Darmstadt, Germany, for the Climate Symposium. This was a conference organized by EUMETSAT (one of the European space agencies) and the World Climate Research Program.

The conference had a couple of goals. Perhaps most prominent was to “ascertain critical objectives to be achieved with satellite-based climate information, and identify gaps in the current space-based component of the climate observing system” – in other words, help EUMETSAT decide what new satellite instruments to build and launch in the coming years. The idea here was to present the current state and future needs of climate science in order to determine how new satellite observations could help. The climate science was presented through the lens of WCRP’s new Grand Challenges. (I am involved directly in one of these, on Clouds, Circulation and Climate Sensitivity, and interacting with the leaders of another, on Understanding and Predicting Weather and Climate Extremes.)

Climate science justifies its funding largely on the basis of its benefit (real or potential) to society, and that justification was particularly explicit at this conference. A lot of the program was devoted to “Climate Services”. This term refers to entities and people whose jobs lie in between the physical science of climate and “users” of climate information, also known as “stakeholders”. Climate Services involves translating the information that climate science can provide into terms that will be most useful for specific human purposes. (In the US, NOAA tried a few years ago – at the instruction of President Obama – to create a National Climate Service, with a status analogous to the National Weather Service. Congress, much of which hates even the word “climate”, killed it.) In practice, Climate Services is about taking the time to learn what specific users’ needs are, teaching those users what climate information current science can and can’t provide, and packaging the information to make it easier for them to digest.

Most of what I know about Climate Services comes from the International Research Institute for Climate and Society (IRI) at Columbia, which has been providing climate services since well before I (or most other people) ever heard the term. I was initially hired at Columbia through the IRI, which came into being a couple of years before I arrived here in January 2000. The IRI, in turn, exists because of the work of Mark Cane.

In the 1980s, Mark and his then student Steve Zebiak (later to become a founding member, and then director of IRI) developed the first numerical model that was capable of predicting the El Niño/Southern Oscillation (ENSO) phenomenon. They demonstrated this by making a successful prediction of the 1986/87 event.

While ENSO occurs in the equatorial Pacific, it has influences on climate and weather across much of the earth. An El Niño, for example, typically causes drought in Australia, Indonesia, southern Africa, and northeast Brazil, wet weather in southern California and unusually clear weather in the Pacific Northwest, and fewer hurricanes in the Atlantic, among other changes. Cane and Zebiak realized that the forecast capability they had developed had the potential to make a positive difference to the lives of a substantial fraction of the planet’s population. By knowing something about how the upcoming season or two would be likely to differ from the usual, people and governments could plan ahead across many sectors of activity: agriculture, water, health.

The IRI was created to realize that potential, and has been working with countries around the world for over 15 years to that end. While the notion of Climate Services now is as much about long-term anthropogenic climate change as it is about interannual variability (a la ENSO), ENSO and the IRI were at the start of it as much as anything, and are still a critically important component.

Tomorrow – Monday October 20 – we will start The Tropics Rule, a Symposium Honoring Mark Cane’s Contribution to Climate Science. This will be a two-day event on the occasion of Mark’s 70th birthday, featuring a long list of distinguished scientists presenting new research and historical reflections on Mark’s long career of truly amazing scientific achievements. It will take place in Monell Auditorium, the physical home of the IRI, on the Lamont Campus.

So in summary, I got on a plane to fly to Germany for a conference where I heard about the present and future of Climate Services. Then I got back on a plane to fly home to attend another conference at my own institution, in honor of the scientist who, it is not a great exaggeration to say, invented the idea.

Back to school heat in NYC

In New York City, today’s temperature was forecast to be hotter than any yet this summer (though it hasn’t got there yet, there is still time). This is a little unusual since it is already September. I got an inquiry from a reporter today, containing the following questions:

“This summer’s seemingly mild weather was actually warmer than average.  Has climate change caused us to have a new normal?  And while  a 92 degree day on September 2nd is not unheard of, is there a larger case of climate change going on?”

Here is the answer I sent, edited and expanded a bit for this post:

Yes, there is certainly a new normal as far as temperature is concerned. It was a cool summer compared to recent decades, but those have been warm compared to the longer-term historical record, due in large part to human-induced global warming. Thus this summer was still warm compared to the long-term average (which means, since the mid-19th

It’s worth also mentioning that the coolness this summer was limited to our half of the country; the west was extremely hot even compared to recent years, with bad forest fires in the Pacific NW, the drought in California etc.

One can’t assign the hot weather today to global warming though – at least not for the most part. It’s never a good idea to attribute a single day of weather to long-term trends, because the natural day-to-day (and even month-to-month or year-to-year) fluctuations are large. On the other hand, it is safe to say that global warming will mean more 92-degree days after Labor Day in years to come, compared to the past.

Because of natural variability, some summers are a little warmer, some are a little cooler. But global warming keeps continuously pushing them all warmer. So by sometime in mid-century, the coolest summer in any given decade is still very likely to be hotter than even the hottest summer that anyone alive now (or their parents, grandparents etc.) has yet experienced.

Climate Central did a nice piece recently which includes an online form allowing you to see how this summer stacked up against the historical record for many US cities. Here is the image I got by selecting San Francisco, where this summer broke the all-time record according to the graph – I’m not sure why the title is just “Near Record Warmth”. The bars are the different years ranked by their average temperature.