Weighting for Averages

First things first: to Grit, and Brit, to all readers and all the world: Happy New Year!!!

I was glad to receive a response from The Grit to my last post in our continuing dialogue concerning global warming.

I see two problems with the information you present.

First, area-weighting of the data is very suspicious. It implies that some areas are not well measured, which means that small errors in taking the measurements would be magnified. Also, with scanty placement of measuring equipment, local variations will not get filtered out.

Svalbard Saga

Thanks to nooneinparticular for pointing out an interesting news story reported in the Sydney Morning Herald:

Norway will invite US politicians to visit a group of fast-thawing Arctic islands in 2007, hoping to win converts for tougher action against global warming, its foreign minister says.
…
Stoere said the Svalbard archipelago, 1,000km (620 miles) from the North Pole, where melting glaciers and thawing sea ice is disrupting the lives of people and animals such as polar bears, could be a showcase in 2007 for the effects of warming.

What struck me is that just today I was looking at temperature data from ECA for Svalbard, Norway! If the Norwegian government persuades American (and other) politicians to visit Svalbard, what will they see?

Temperature Records of the Week

A certain global warming denialist website, co2science, regularly posts a “temperature record of the week.” I showed how they use clever cherry-picking to make their case look good in another post. But hey, two can play at that game; I too can post a “Temperature Record of the Week.” In fact, I’ll post two.

Same Old Same Old

I recently encountered a blog post which expressed concern about, and the need for action on, global warming, while objecting to the demonization of conservatives on the issue, and expressing distaste for Al Gore and his approach. What caught my eye was not the post itself, but a comment made by a reader, denying the reality of global warming, the science behind it, and the danger inherent.

The arguments given are basically the same-old-same-old denialist arguments I’ve heard for years. But just as they are repeated again and again and again, it’s important for them to be refuted again and again. So, here goes.

Breaking the Ice

Before getting to the main topic of today’s post, I’ll mention that there’s a terrific story from a Belgian who attended the training session to become a presenter of Al Gore’s slide show about global warming: http://www.worldchanging.com/archives/005588.html. Quite a good read! The cavalry is coming — and we’re it.

A few days ago I posted about ice-out (day of breakup of the ice) on Moosehead Lake. I pointed out that it’s far too easy to get the wrong idea from a cursory look at data, that in fact the data presented did not show signs of global warming, but that more up-to-date data actually does. When I went hunting for ice-out data for Moosehead Lake, I actually found data for 29 lakes in New England. So I’d like to discuss what the data show.

Al Gore

Last night I co-hosted a viewing party for Al Gore’s film An Inconvenient Truth. We had about 23 people in attendance. Most were already concerned about the issue, and a few already knew a lot about it. But the film provided much information for most of the attendees, and raised the level of concern; it galvanized folks to want to do something. Our primary hostess had a lovely home with a big room for viewing and a big-screen TV. We also had a visit from a local state representative (John Brautigam) who said a few words about environmental issues in Maine; he’s received a 100% rating on environmental issues from the Maine League of Conservation Voters.

Moosehead Lake

It’s not easy separating the valid from the invalid, when it comes to scientific evidence about global warming.

I recently visited the website of the Maine League of Conservation Voters. It’s a pro-environmental group in my home state that lobbies for environmental issues and tracks the environmental voting record of our state legislators. They feature “factoids” about environmental issues, including this one about climate change:

The date of “ice out” on Moosehead Lake has been reported since 1848. Trends indicate that it is melting at increasingly earlier dates, suggesting milder winters and earlier spring conditions. To view a complete data table and graph of Moosehead Lake’s “ice out” dates, click here.

Of course I clicked through (I’m always after more climate data), and found this graph together with numerical data:

Clearing the Air

The Grit has helped me understand the importance of clarity in communication, and some of the ways in which I tend to be unclear.

While I do see some of your information as interesting, I still need to know more details. For instance, when you talk of global average temperature increases, what exactly do you mean. It could be that every place on Earth has an increased temperature, or one small area has a greatly increased temperature. This to me, and I suspect others, is confusing.

Excellent point. It highlights the fact that some things which are second nature to me are unknown (and therefore often confusing) to others, and that I often use terminology which is transparent to me, but not to readers.

Balloons and other things

In response to my last post, the Grit posted further doubts. I responded inline to his comment, but it deserves a more detailed response, particularly for the issue of balloon-borne temperature measurements of tropospheric temperature.

At issue is the claim in a web page from NASA’s Marshall Space Flight Center that satellite measurements of temperature in the lower troposphere (the lower layer of earth’s atmosphere) are not rising, contradicting computer models which indicate it should be warming at least as fast as surface temperature.

So let’s start with the Grit’s comments:

Satellites

In our continuing dialogue concerning global warming, Brit and Grit have mentioned a web page which indicates that the satellite-derived temperature record for the lower troposphere (the lower part of the atmosphere) shows no warming, perhaps even a slight cooling, while the instrumental surface temperature record indicates strong warming (about 0.18^oC/decade) for the last 30 years or so. This strongly contradicts the results of computer models, which indicate that the lower troposphere should be warming at about the same rate as, probably even faster than, surface temperature. Hence there was a large discrepancy between the predictions of computer models and observed temperature trends in the lower troposphere. I’ve been aware of this issue for some time (in fact I’ve been meaning to post on it for a while now).