Zero Carbon Australia: We can do it

I wrote this post for Skeptical Science.

My recent post about long-term CO₂ targets was rather doom-and-gloom: I concluded that we must phase out fossil fuels to keep the climate in the range that humans have experienced. The good news is that action on this scale is not only possible but surprisingly feasible.

Last year, the University of Melbourne Energy Research Institute in conjunction with Beyond Zero Emissions produced the Zero Carbon Australia 2020 Stationary Energy Plan. The ZCA2020 Plan outlines an ambitious and inspiring vision: to power Australia with 100% renewable energy in ten years.

The report that has been released only covers emissions from Stationary Energy (though it does refer to electrifying transport). Five future reports are planned on how to eliminate emissions from other sectors (Transport, Buildings, Land Use and Agriculture, Industrial Processes, and Replacing Fossil Fuel Export Revenue).

Why do it, and why now?

As I’ve explained here, to prevent “dangerous anthropogenic interference with the climate system” we must reduce CO₂ to below 350 ppm. That necessitates a rapid transition to a zero-carbon economy.

A common approach is to define a quota of allowable future global emissions to limit warming to less than 2°C above predindustrial levels, and divide them up by nation per capita. At Australia’s current rate of emissions, we will use up our share of the global budget in just five years (the same goes for the US and Canada). This gives Australia about a decade to make the transition.

Do the IPCC use alarmist language?

This post was written for Skeptical Science.

Graham Wayne has recently written rebuttals to “The IPCC consensus is phony” and “IPCC is alarmist”. But, you might say, that’s only half the story – do the IPCC present their conclusions in an alarmist way? There are many different ways you might look at this, but one of the more important ones is how the IPCC present probabilities (or “likelihoods”).

Thinking about probability does not come intuitively to the human mind. Our assessment of a risk often depends on how the probability is presented.

Suppose you are about to get on a plane and a reliable source tells you that there is a 1% chance that the plane will crash during your flight. Do you still want to get on the plane? I’m guessing you’d be having second thoughts about it.

What if the probability of a crash is 1 in 20? 1 in 10? 1 in 3? You’d probably run away screaming.

I’ll get to the point of all this shortly, but please bear with me and consider the following quote from the IPCC’s Fourth Assessment Report (AR4):

It is very unlikely that [Atlantic Ocean circulation] will undergo a large abrupt transition during the 21st century. [Source]

Are you alarmed yet? Is this an example of the IPCC using alarmist language in reporting its conclusions?

My First Election

I don’t intend to talk much about politics on this blog, but in this case I’ll make an exception. Australia will have its 43rd federal election on the 21st, and I am a first-time voter. In a follow-up post either later today or tomorrow, I’ll get into a bit of politics — and given the subject matter of my blog, I’ll mostly be talking about climate policy — but for now, a bit of background about, and analysis of, the Australian electoral system.

Voting is compulsory, though it’s a secret ballot so voters are free to “vote informally” by leaving their ballot paper blank or incorrectly filled in. There are two houses of Parliament: the lower house is called the House of Representatives, and the upper house is the Senate. The House has 150 members, who serve three-year terms and are elected from single-member electorates. Each electorate is supposed to contain more or less the same number of voters (though the rules are complicated, and in practice the number can vary from around 60,000 to around 120,000).

In House of Representatives elections, Australia uses a preferential voting system called instant-runoff voting. Voters must number all the candidates on the ballot paper in order of their preference. If one candidate receives more than 50% of the first-preference votes then they are declared elected. If not, the candidate with the least votes is eliminated and their votes are redistributed according to the second preferences of each person who voted for that candidate. This process continues until one candidate passes the 50% benchmark.

Global Warming Contrarians Part 7: State of the Climate

Claim: There’s no evidence that the global climate is warming. Why worry about a problem that’s invisible?

Fact: Just about any aspect of climate you care to look at does show signs of global warming.

The US National Oceanic and Atmospheric Administration have recently released their 20th annual State of the Climate report. The report is ostensibly about the climate in 2009, but because 2009 was the end of a decade the authors decided to take a longer-term view.

According to the press release, the report

draws on data for 10 key climate indicators that all point to the same finding: the scientific evidence that our world is warming is unmistakable. More than 300 scientists from 160 research groups in 48 countries contributed to the report, which confirms that the past decade was the warmest on record and that the Earth has been growing warmer over the last 50 years.

Scientific Opinion versus Media Balance

Renegade Conservatory Guy has created an infographic showing the discrepancy between scientific opinion on global warming and public opinion. I think this speaks for itself.

Mid-Year Update on Global Temperatures

NOAA’s National Climatic Data Center (NCDC) have announced that the Earth has just experienced its warmest June on record, 0.68°C warmer than the 20th-century June average of 15.5°C. Most of the globe was warmer than usual, with the highest temperature anomalies seen in eastern and western Asia, eastern North America, western South America, and most of the Atlantic Ocean. The only surface temperatures much cooler than average were in the eastern Pacific and Southern Oceans. The warmest June is particularly notable in that it follows the warmest March, April, and May.

(Global temperatures are usually given as anomalies relative to a 20th century average because they are easier and more useful to compare than absolute temperatures. The last month with a temperature below average was February 1985.)

Let’s quickly recap the year so far. It began with an unusually cold winter in northern land areas, related to the Arctic Oscillation (AO), which in February 2010 was at its most negative value on record, moving heat to Arctic regions. Despite the unfortunate and disproportionate impact this had on public opinion, January was a relatively warm month globally, and the Southern Hemisphere had its warmest February on record.

CO2 hits 390 ppm

The level of carbon dioxide (CO₂) in the atmosphere, as measured at Mauna Loa, has just ticked over to 390 ppm.

Actually, that’s not quite true — the level is 392.39 ppm as of April. But CO₂ levels are slightly higher during the northern spring than the southern spring, because the Northern Hemisphere has more land and hence more vegetation breathing out CO₂. Once you adjust for this seasonal cycle, then the current CO₂ level is 389.64 ppm — which rounds to 390.

I first got interested in global warming about four years ago when I read TIME magazine’s special issue on global warming. At that time, the CO₂ level (again, seasonally adjusted) was around 382 ppm. It reached 383 ppm by December 2006, 384 ppm by April 2007, 385 ppm by November 2007, 386 ppm by June 2008, 387 ppm by January 2009, 388 ppm by August, 389 ppm this February, and now 390 ppm. All these numbers come from measurements made at Mauna Loa observatory, but wherever you look you’ll get similar results.

CO2 at Mauna Loa since 2006. (Source: Earth System Research Laboratory)

Did Spanish Astronomers Steal A Dwarf Planet?

In 2005, a controversy erupted in the world of astronomy over who should be credited with the discovery of a distant dwarf planet then known by the temporary name 2003 EL₆₁. The object in question is located in the Kuiper Belt, a doughnut-shaped icy region of the solar system that lies beyond Neptune. It is classified as a “dwarf planet” — which, counter-intuitively, is not actually a planet. According to the International Astronomical Union (IAU), the official naming body in astronomy, a planet must

(a) orbit the Sun,

(b) be massive enough to have a spherical shape,

(c) be massive enough to dominate its region of the solar system, and

(d) not be a moon.

Dwarf planets are almost planets but not quite – they satisfy criteria (a) and (b), but not (c). There are four other objects officially classified as dwarf planets (although many more may qualify): Ceres, the largest object in the asteroid belt between Mars and Jupiter; Pluto, a large Kuiper Belt Object (KBO); Makemake, another large KBO; and Eris, a large object in the region beyond the main Kuiper Belt, the scattered disk.

Pluto has been known for decades and Ceres for centuries, but Eris and Makemake are much more recent finds, discovered in 2005 by a group of astronomers led by Mike Brown at the Department of Geological and Planetary Sciences at Caltech. As for 2003 EL₆₁, not only has Brown’s team claimed its discovery, but so has a rival team led by Jose-Luis Ortiz of the Andalusian Astrophysics Institute in Granada, Spain.