Climate Climate & Energy

‘The CO2 rise is natural’–No skeptical argument has been more definitively disproven

(Part of the How to Talk to a Global Warming Skeptic guide)

Objection: It's clear from ice cores and other geological history that CO2 fluctuates naturally. It is bogus to assume today's rise is caused by humans.

Answer: We emit billions of tons of CO2 into the air and, lo and behold, there is more CO2 in the air. Surely it is not so difficult to believe that the CO2 rise is our fault. But if simple common sense is not enough, there is more to the case. (It is worth noting that investigation of this issue by the climate science community is a good indication that they are not taking things for granted or making any assumptions -- not even the reasonable ones!)

Navajo protest third coal-fired plant on reservation land

Members of the Navajo Nation and their supporters have been blockading the site of a proposed coal-fired power plant in northwestern New Mexico for more than a week now, hoping to halt construction of what they believe will be a social and ecological disaster.

If completed, the Desert Rock Power Plant will cover 600 acres in the largest American Indian reservation in the nation, and it will be the third coal-fired plant on Navajo land.

Let’s not fetishize size

Many environmentalists are reverse size queens -- "small is beautiful."

When Schumacher wrote the book of that title, he was responding to a real tendency to ignore diseconomies of scale -- a tendency that still exists. Up to a certain point, both organizations and physical plants produce more output for each unit of input as they grown in size. Past that point, costs of gigantism kick in, and efficiency begins to fall instead of rising.

But Schumacher assumed that this point always occurs at small or medium sizes. In fact, there are many cases in which you get economies of scale up to very large sizes indeed.

For example, computer CPUs are still made in giant factories, not neighborhood plants; your computer would cost a whole lot more if that were not the case.

‘Natural emissions dwarf human emissions’–But emissions are only one side of the equation

(Part of the How to Talk to a Global Warming Skeptic guide)

Objection: According to the IPCC, 150 billion tonnes of carbon go into the atmosphere from natural processes every year. This is almost 30 times the amount of carbon humans emit. What difference can we make?

Answer: It's true that natural fluxes in the carbon cycle are much larger than anthropogenic emissions. But for roughly the last 10,000 years, until the industrial revolution, every gigatonne of carbon going into the atmosphere was balanced by one coming out.

What humans have done is alter one side of this cycle. We put approximately 6 gigatonnes of carbon into the air but, unlike nature, we are not taking any out.

‘Climate is always changing’–That doesn’t mean it isn’t different today

(Part of the How to Talk to a Global Warming Skeptic guide)

Objection: Climate has always changed. Why are we worried now, and why does it have to be humans' fault?

Answer: Yes, climate has varied in the past, for many different reasons, some better understood than others. Present-day climate change is well understood, and different. Noting that something happened before without humans does not demonstrate that humans are not causing it today.

‘The null hypothesis says warming is natural’–An inappropriate test, and one that would fail anyway

(Part of the How to Talk to a Global Warming Skeptic guide)

Objection: Natural variability is the null hypothesis; there must be compelling evidence of an anthropogenic CO2 warming effect before we take it seriously.

Answer: The null hypothesis is a statistical test, and might be a reasonable approach if we were looking only for statistical correlation between increasing CO2 and increasing temperature. But we're not -- there are known mechanisms involved whose effects can be predicted and measured. These effects are the result of simple laws of physics, even if their interactions are quite complex.

‘Volcanoes emit more CO2 than humans’–Not even close …

(Part of the How to Talk to a Global Warming Skeptic guide)

Objection: One decent-sized volcanic eruption puts more CO2 in the atmosphere than a decade of human emissions. It's ridiculous to think reducing human CO2 emissions will have any effect.

Answer: Not only is this false, it couldn't possibly be true given the CO2 record from any of the dozens of sampling stations around the globe. If it were true that individual volcanic eruptions dominated human emissions and were causing the rise in CO2 concentrations, then these CO2 records would be full of spikes -- one for each eruption. Instead, such records show a smooth and regular trend.

(image from Global Warming Art)

‘Mars and Pluto are warming too’–No they aren’t — and what if they were?

(Part of the How to Talk to a Global Warming Skeptic guide)

Objection: Global warming is happening on Mars and Pluto as well. Since there are no SUVs on Mars, CO2 can't be causing global warming.

Answer: Warming on another planet would be an interesting coincidence, but it would not necessarily be driven by the same causes.

The only relevant factor the earth and Mars share is the sun, so if the warming were real and related, that would be the logical place to look. As it happens, the sun is being watched and measured carefully back here on earth, and it is not the primary cause of current climate change.

It’s disheartening

... can be found here (hat tip to pollster.com).

Here's the important result:

American voters tend to see Global Warming as a serious problem but are divided as to whether it's caused by human activities or long-term planetary trends.

This is important because:

Heat, hotness, and hotitude

Here are the second five of my "Top 10 climate stories of 2006," in no particular order. (The first five are here.)

2005 was hot: In early 2006, it was revealed that 2005 was a statistical tie with 1998 for the hottest year of the past 400. However, 1998 was warmed by the biggest El Nino of the 20th century, while 2005 had no such help. That means something else contributed to making 2005 so warm, and that something was almost certainly human activity. With a mild El Nino going on right now, my prediction is that 2007 will eclipse 1998 and 2005 as the hottest year of the instrumental record.