Mar 04 2010

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. Continue reading

Feb 20 2010

Global Warming Contrarians Part 2: 1998, El Niño, and Ocean Heat Content

This is the second in a series of posts on the arguments contrarians make against global warming. In Part 1, I discussed long-term global temperature trends, criticisms of the surface temperature record, and cold weather. And without further ado, I’ll continue by looking at another popular claim about global temperatures…

Claim: Global warming stopped in 1998.

Fact: The warmest year on record is 2005 (14.52°C, or 0.62°C above the 20th century average), followed by 1998 (14.50°C). But this does not mean the Earth has been cooling since 1998. 2009 came in at sixth warmest (14.46°C), the years 2001-2009 all make the top ten, and the top 14 have all occurred since 1995 — so at the very least, we can say the Earth hasn’t cooled. The 2000s was the warmest decade (14.44°C), followed by the 1990s (14.26°C) and 1980s (14.10°C).*

Average global temperatures for each decade on record compared to each year. (Source: NCDC)

Continue reading

Feb 13 2010

Why the Global Warming “Skeptics” Are Wrong – Part 1: Tracking Temperatures

Mark Twain once said, or at least is supposed to have said: “A lie can travel halfway around the world while the truth is putting on its shoes.” The climate change contrarian blogosphere that has recently emerged is rather like that. Every month, there is some new argument being passed around that “disproves” global warming or the integrity of climate science in general, and it is amplified in blogs and opinion columns worldwide. These global-warming-disproved memes seem to have had something of a revival recently, which is ironic considering that the scientific evidence, if anything, has moved in the opposite direction: the evidence for global warming is now stronger, and more alarming, than ever.

This will be the first in a series of posts on the arguments contrarians make against global warming.

Claim: The Earth isn’t warming.

Fact: The Earth’s surface has warmed about 0.72°C in the last century, and about 0.18°C/decade in the last quarter-century.* Before the 1970s, the trend was much slower and disguised by large fluctuations, including a slight cooling in the mid-20th century (which I’ll discuss in a future post). Continue reading