Posted by Max Dunn
Fri, 01 Feb 2008 15:53:19 GMT | no comments
I have been reticent to publicly state my beliefs about global warming for a few reasons. One is that some of my friends are global warming believers and I don’t want to offend them. Another is that the global warming movement has gained so much momentum that it has becoming a core-belief of our society and to speak against it often makes a person seem crazy.
But the time has come for me to state my beliefs, and here they are:
- Many parts of the world are experiencing rising temperatures or other climate changes
- Man’s activities are increasing the amount of CO2 in the atmosphere
- This increased CO2 is contributing in part to climate changes
- The effects from man’s contribution to climate change will not be as bad as many claim
On the other hand, I do believe that peak oil is going to be a gigantically huge problem and will be a major inflection point in the development and lifestyle of all civilization on this planet.
Conveniently, the actions to reduce CO2 are almost exactly the same ones that will help with peak oil. So I don’t mind riding the global warming train for now since it leads to the same place eventually!
Posted in Global Warming
Posted by Max Dunn
Thu, 31 Jan 2008 00:16:29 GMT | 1 comment
It is common knowledge that buses are energy efficient, right? I mean shouldn’t we all ride the bus rather than drive a car? Well a study looked at this more closely and found out something interesting. Here are some figures for passenger miles per gallon (PMPG) for various forms of transportation:
- Light rail – 120 PMPG
- Trolley bus – 104 PMPG
- Commuter rail – 86 PMPG
- Intercity rail – 66 PMPG
- Car, average trip – 44 PMPG
- Transit bus – 33 PMPG
Wow, look at that: city buses only get about 33 PMPG – this is even less than a normal car with 2 people which gets 44 PMPG! I guess to be more green, we should all avoid the bus and drive our cars instead. :-)
Reference: Comparison of Energy Use & CO2 Emissions From Different Transportation Modes
Posted in Global Warming, Peak Oil
Posted by Max Dunn
Wed, 09 Jan 2008 04:10:37 GMT | no comments
In my son’s 7th grade social studies class today, he was given an article that discussed how the warming of the Antarctic was melting ice sheets and reducing the population of some penguin colonies. However, while the breakup of the Larsen B ice shelf was unexpectedly rapid, the Antarctic as a whole has actually had stable or decreasing temperatures and the overall ice pack has probably been growing. Even the IPCC recognizes this by stating:
“Antarctic sea ice extent continues to show interannual variability and localised changes but no statistically significant average trends, consistent with the lack of warming refl ected in atmospheric temperatures averaged across the region.” [1]
Another source confirms that:
“it is also clear from satellite data that surface temperatures decreased during the years 1982 through 2002” and “the Antarctic ice sheet had gained enough mass between 1992 and 2003 to slow sea level rise at a rate of about 1 cm/century” [2]
And one source states:
“over the past four decades, and during the time of the greatest build-up of greenhouse gases, Antarctica has been cooling!” [3]
These observations in no way disprove global warming in general. However, they do clearly show is that climate change is very complex science and that you can’t draw simple or universal conclusions based on it.
[1] IPCC AR4 Summary for Policymakers (Page 9)
[2] Is Antarctic climate changing?
[3] Antarctica: Warming, Cooling, or Both?
Posted in Global Warming
Posted by Max Dunn
Sun, 30 Dec 2007 17:43:32 GMT | 1 comment
When I talk about how clean electric vehicles are, people sometimes ask if they really do reduce greenhouse gases since burning coal to produce electricity creates a lot of CO2. My standard answer to this question is that even in the worst case, electric cars are twice as clean as gas powered cars. However, while reading an article in Forbes about vehicle-to-grid (V2G) systems. I realized that in general, electric cars are much cleaner than even this.
This article had an interesting chart that said electric cars produce about 1.1 tons of greenhouse gases a year while gas powered cars produce 6.3 tons – over 6 times more! Let’s see if we can verify these numbers.
The average car is driven 15,000 miles per year and electric vehicles normally get 4 miles per kWh, so it takes about 3,750 kWh of electricity a year to power an electric car. In California, the mix of electricity production produces about 0.6 lbs of greenhouse gases per kWh so this would produce 2,250 pounds, or 1.1 tons of greenhouse gases – right on the money with the Forbes chart.
A gas car, on the other hand, produces about 1 lb of CO2 for every mile driven (based on producing 20 lbs per gallon and getting 20 mpg). So 15,000 miles would produce 15,000 lbs of greenhouse gases, or about 7.5 tons – which is more than the Forbes estimate of 6.3 tons (maybe they are using a higher mpg).
So electric cars are even cleaner than I had thought, producing about one sixth as much greenhouse gases as a gas car.
Posted in Electric Vehicles, Global Warming
Posted by Max Dunn
Fri, 21 Dec 2007 19:07:56 GMT | no comments
When trying to discredit a scientist’s work, critics sometimes simply note: “They received funding from XYZZY corporation.” It is interesting that often nothing more is said, as if it is apparent that taking any money from a party with a vested interest will inevitably skew the results. This seems like a pretty harsh position, but there is some basis to this claim.
For instance, new research looked at drug studies and found that while the results of the study were not likely to be biased, the conclusion from those results were. In particular, they found that studies funded by a single drug company have a 55% rate of favorable results that is transformed into a 92% rate for favorable conclusions, representing a 37% gap. The gap shrinks to 21% (57% to 79%) when two or more drug companies provide support. Yet the gap vanishes entirely for studies done by non-profit institutions alone or even in conjunction with drug companies. These findings suggest a disconnect between the data that underlie the results and the interpretation or “spin” of these data that constitutes the conclusions.[1]
So it is apparent that receiving funding from a particular source that has a vested interest in the outcome will likely affect the conclusion of a study.
But are there other biases besides funding sources that can affect the results or conclusions of scientific work? What if a researcher isn’t taking any outside funding but has a passionate belief about what they are researching – will this affect their work as well?
Read more...
Posted in Random Thoughts, Global Warming
Posted by Max Dunn
Sat, 08 Dec 2007 17:52:03 GMT | no comments
The global temperature graph that appears in An Inconvenient Truth and also the one that the IPCC uses is usually referred to as the Mann or MBH98 graph.
However, this temperature reconstruction is controversial. One of its problems is that it doesn’t show the Medieval Warming Period or the Little Ice Age (LIA).
More recently, Loehle put together another temperature reconstruction
that doesn’t use tree rings and this reconstruction does show the MWP and LIA.
Posted in Global Warming
Posted by Max Dunn
Sat, 08 Dec 2007 17:36:22 GMT | no comments
When talking to people about religion, you have to be careful. Many people don’t want to hear facts or ideas that contradict their point of view; they are only interested in hearing things that reinforce what they already believe.
This same phenomenon also happens when talking about global warming – most people have their minds made up on this issue and aren’t willing to consider any evidence that would challenge their beliefs.
Posted in Global Warming, Random Thoughts
Posted by Max Dunn
Fri, 14 Sep 2007 03:36:04 GMT | 8 comments
There is a growing interest in buying carbon credits to offset our carbon footprints. However, there is evidence of widespread failings in the market for carbon offsets. Some of these failings include:
- Widespread instances of people and organisations buying worthless credits that do not yield any reductions in carbon emissions.
- Industrial companies profiting from doing very little – or from gaining carbon credits on the basis of efficiency gains from which they have already benefited substantially.
- A shortage of verification, making it difficult for buyers to assess the true value of carbon credits.
In addition, many carbon offset projects don’t pay for the whole cost of CO2 removal projects they just kick in a little money and claim all the carbon credit of the project. Is this really going to significantly reduce the amount of CO2 in the atmosphere?
Read more...
Posted in Global Warming