Dawn Patrol

March 30, 2012

Republican presidential Candidate Rick Santorum on climate change:

I believe the earth gets warmer and I also believe the earth gets cooler, and I think history points out that it does that and that the idea that man, through the production of CO2 — which is a trace gas in the atmosphere, and the manmade part of that trace gas is itself a trace gas — is somehow responsible for climate change is, I think, just patently absurd. [..]
To me this is an opportunity for the left to create — it’s really a beautifully concocted scheme because they know that the earth is gonna cool and warm. It’s been on a warming trend so they said, ‘Oh, let’s take advantage of that and say that we need the government to come in and regulate your life some more because it’s getting warmer.’ [..]
It’s just an excuse for more government control of your life and I’ve never been for any scheme or even accepted the junk science behind the whole narrative.

Megadeth front man Dave Mustaine on Rick Santorum:

You know, I think Santorum has some presidential qualities, and I’m hoping that if it does come down to it, we’ll see a Republican in the White House… and that it’s Rick Santorum.

and:

[Santorum] just looks like he could be a really cool president, kinda like a JFK type of guy.

Lyrics to Megadeth’s Dawn Patrol:

Thermal count is rising
In perpetual writhing
The primordial ooze
And the sanity they lose
Awakened in the morning
To more air pollution warnings
Still we sleepwalk off to work
While our nervous systems jerk
Pretending not to notice
How history had forebode us
With the green house in effect
Our environment was wrecked
Now I can only laugh
As I read our epitaph
We end our lives as moles
In the dark of dawn patrol

Dave… what gives?

 

[ Note that, as usual, I’ve added direct links to refutations of the scientifically wrong statements, thanks to Skeptical Science, where links to the scientific literature can be found as well. In their words: Climate reacts to whatever forces it to change at the time; humans are now the dominant forcing. The strong CO2 effect has been observed by many different measurements. The natural cycle adds and removes CO2 to keep a balance; humans add extra CO2 without removing any. ]


Peter Gleick, Another Green Hero

February 22, 2012

Tim DeChristopher

Remember Tim DeChristopher?

While Tim was taking his final exams at the University of Utah, advocates for Utah’s wilderness like Robert Redford and the Southern Utah Wilderness Alliance were attempting to bring attention to a controversial auction of Utah public lands, orchestrated by the outgoing Bush Administration. The auction included parcels adjacent to cherished natural resources like Canyonlands National Park. SUWA and other regional advocates brought a lawsuit against the Bureau of Land Management in efforts to halt the auction pending further review and public comment. Through no fault of SUWA or their allies, the lawsuit could not settle the issue prior to the auction. On December 19th, Tim finished his last final exam and took TRAX to the protest that SUWA and others had organized outside of the auction. On arrival, Tim decided that the protest needed to be moved from outside of the auction to inside, where the action was happening. With no prior plan of action, Tim entered the building where the auction was held and approached the registration desk. When asked if he was there to bid, Tim made a quick decision. He registered as Bidder 70 and entered the auction

Without the legally required environmental reviews the auction itself was mostly illegal, which was obvious from the start and confirmed eventually (‘In the end, of the 116 leases, only 29 are found to be legal‘). For his succesfull effort in saving these lands, close to Arches and Canyonlands national parks, for future generations to enjoy and for succesfully preventing an illegal auction, Tim DeChristopher ended up in jail. At the time of writing, he is still imprisoned and serving a two year sentence for doing the right thing.

I was reminded of DeChristopher as I watched the unfolding of the recent events surrounding the public release of the internal documents of the nihilistic opinion mercenaries at Heartland Institute. As a parent, as a scientist and as a decent human being I stand in awe of Peter Gleick as I stood in awe of DeChristopher’s moral courage.

Peter Gleick

A quick recap: per his own words, Gleick received an anonymous document detailing the Heartland Institute’s climate program strategy and containing information about their funders and the Institute’s apparent efforts to muddy public understanding about climate science and policy. Intrigued (and realizing the obvious that he was never intended to see said document) he subsequently solicited and received additional materials directly from the Heartland Institute under someone else’s name. Gleick called his latter action a lapse of ethics –I don’t. I call it investigative journalism, something that a serious reporter on enviromental issues could have done a long time ago (like NY Times’ Andy Revkin… just kidding, the Heartland documents show that even they view him as a complete tool)

The leaked documents reveal a number of things:

  • Heartland claims the tax statust of a501(c)(3) non-profit organisation on its IRS forms, which forbids its from lobbying and attempting to influence legislation. However, they do just that, for example as part of what they call project angry badger

    Wisconsin was the focus of national attention due to recall campaigns waged in 2011, and campaigns are taking place in 2012 against Gov. Scott Walker, Lt. Gov. Rebecca Kleefisch and three Republican senators who voted for Act 10, the landmark collective bargaining reform legislation adopted in 2011. We have been following the Wisconsin debate closely, reporting on it in Budget & Tax News, commenting in op-eds and LTEs and on blogs, doing television and radio interviews, and sending research and commentary to elected officials in Wisconsin and nationally. [hello! IRS! That’s lobbying right here!] [..] Heartland is the largest and most influential national free-market think tank in the Midwest, so we are in the right place and with the right resources to help defend and secure Wisconsin’s recent gains

  • Climate denialist bottom feeder Anthony Watts, who runs the website Watts up what that? has always claimed his work was a labor of love (see here for example, although Watts has a habit of altering his posts once they become inconvenient for him. He is a very busy man). In the words of Heartland:

    Anthony Watts proposes to create a new Web site devoted to accessing the new temperature data
    from NOAA’s web site and converting them into easy-to-understand graphs that can be easily found and understood by weathermen and the general interested public. Watts has deep expertise in Web site design generally and is well-known and highly regarded by weathermen and meteorologists everywhere [citation needed!]. The new site will be promoted heavily at WattsUpwithThat.com. Heartland has agreed to help Anthony raise $88,000 for the project in 2011. The Anonymous Donor has already pledged $44,000. We’ll seek to raise the balance.

    It is a delicious twist of irony that the one temperature data project Watts has actually contributed to (as n-th author on a peer-reviewed paper) ended up clearly debunking his thesis that temperature stations were unreliable

  • Speaking of Anonymous Donors, there apparently exists some obscenely rich lunatic who is willing to consistently provide the bulk of Heartland’s funding. His identity is still unclear (Voldemort? It is telling that even in internal memo’s and documents he was Not To Be Named), but his donations for the past few years have been as follows: $3,276,937 (2007), $4,600,000 (2008), $2,822,180 (2009), $1,664,150 (2010), $979,000 (2011), $1,250,000 (2012). Each year, the majority of the donation was used for `Global Warming Projects‘.
  • A Global Warming project of note is the preparation of additional material for K12-schools (get ’em while they’re young):

    Many people lament the absence of educational material suitable for K-12 students on global warming that isn’t alarmist or overtly political. Heartland has tried to make material available to teachers, but has had only limited success. Principals and teachers are heavily biased toward the alarmist perspective. Moreover, material for classroom use must be carefully written to meet curriculum guidelines, and the amount of time teachers have for supplemental material is steadily shrinking due to the spread of standardized tests in K-12 education. [..]
    Dr. Wojick proposes to begin work on “modules” for grades 10-12 on climate change (“whether humans are changing the climate is a major scientific controversy”), climate models (“models are used to explore various hypotheses about how climate works. Their reliability is controversial”), and air pollution (“whether CO2 is a pollutant is controversial. It is the global food supply and natural emissions are 20 times higher than human emissions”).

    Note that all statements in quotes are factually wrong and I’ve turned them into to links where you can find clear debunkings with references to the scientific literature (thanks to Skeptical Science!). In the one document that Heartland claims is fake (although there is absolutely no reason to believe so, given its overall consistency with documents like the 2012 fund-raising plan that I have quoted from so far) they even seem to be aware of the fact that they’re selling plain lies to children:

    His effort will focus on providing curriculum that shows that the topic of climate change is controversial and uncertain – two key points that are effective at dissuading teachers from teaching science.

  • Heartland generously funds the usual professional liars with monthly stipends:

    Our current budget includes funding for high-profile individuals who regularly and publicly counter the alarmist AGW message. At the moment, this funding goes primarily to Craig Idso ($11,600 per month), Fred Singer ($5,000 per month, plus expenses), Robert Carter ($1,667 per month), and a number of other individuals [..]

    I’ve added links to Sourcewatch where you can find additional information on these characters. Earlier in his career, Fred Singer for example has been a mouthpiece for the tobacco industry and has argued that DDT is harmless. Complete bastards, all.

  • Finally, Heartlands take on the current media landscape and who they view as useful idiots for their cause:

    Efforts at places such as Forbes are especially important now that they have begun to allow high-profile climate scientists (such as Gleick) to post warmist science essays that counter our own. This influential audience has usually been reliably anti-climate and it is important to keep opposing voices out. Efforts might also include cultivating more neutral voices with big audiences (such as Revkin at DotEarth/NYTimes, who has a well-known antipathy for some of the more extreme AGW communicators such as Romm, Trenberth, and Hansen) or Curry (who has become popular with our supporters)

The fight about public understanding of global warming is a case of asymmetric warfare where one side can make up lies as they go along but scientists are bound to scientific fact, no matter how subtle, counter-intuitive or unwelcome. Given the above information about Heartland, Gleick made the morally right choice in making these documents public. You didn’t hear Heartland cry foul about climategate, the leak of personal e-mails from UK climate scientists. What made climategate so reprehensible in my view was not the act of hacking into e-mails (for what if there was a great conspiracy? The thought is ludicrous for anyone with at least a passing understanding of climate science and not in possession of a tinfoil hat, but let’s humour the seriously misguided souls for a moment), but the coordinated and wilful effort to data mine the e-mails and then releasing a minuscule fraction of them in terms of specific sentences that could be easily taken to mean something different when taken out of context (all spin has subsequently been debunked countless times). And all of that right before important climate negotiations, first in Cancun, then in Ireland.

Hats off to Peter Gleick, another green hero.


No global cooling in Cosmos

July 25, 2011

A while back I started watching the famous documentary series `Cosmos’ by Carl Sagan. The series is very good, although it might take you more than the first episode to appreciate that if you see it today -you’ll have to get past that voice, droning on like reverend Lovejoy from the Simpsons and that ridiculous spaceship that William Shatner wouldn’t be caught dead in. But after a while, Sagan’s voice-over improves and he all but abandons his spaceship to end up presenting a series of fascinating lectures, supported by (mostly) excellent multi-media support.

Global cooling?

Being an astrophysicist myself, most of the science isn’t new to me (some of it is even slightly outdated) and I enjoy the series mostly for the cultural references and historical context. But then something caught my eye in episode 4 when the discussion turned to climate change. You might remember the but in the seventies, it used to be global cooling! meme that has been spread vigorously by fossil-fuel industry funded stooges (e.g. here, unmasked here) or by pop science writers who are really not all that clever. The purpose of the meme is of course to obfuscate and to lead the non-expert to believe that scientific consensus on climate change has been swinging back and forth between wildly diverging opinions over the course of the past decades, thereby diminishing the impact of the current overwhelming consensus in the climate science community that global warming is real, occurring now and is man-made. The whole global cooling story has already been thoroughly debunked (e.g. here, here). Since Cosmos was originally broadcasted in 1980, closer to the global cooling craze than the global warming craze, had the former really existed, it is interesting to hear what Sagan has to tell us about global climate change, if only to as a reminder how scientific consensus actually did emerge over the past decades.

Cosmos, 1980

The destruction of trees and grasslands makes the surface of the Earth brighter. It reflects more sunlight back to space and cools our planet. After we discovered fire we began to incinerate forests intentionally to clear the land by a process called “slash and burn” agriculture. And today, forests and grasslands are being destroyed frivolously, carelessly by humans who are heedless of the beauty of our cousins the trees and ignorant of the possible climatic catastrophes which large-scale burning of forests may bring.

So is Sagan implying here that we should be afraid of global cooling? At least he gives us a concise description of the mechanism. (By the way, the reference to trees as cousins should not be read as some wishy-washy new-ageism, but as a reference to an earlier point in the series where the incredible similarities on chemical and DNA level across the different species were discussed).

The indiscriminate destruction of vegetation may alter the global climate in ways that no scientist can yet predict. It has already deadened large patches of the Earth’s life-supporting skin. And yet, we ravage the Earth at an accelerated pace as if it belonged to this one generation, as if it were ours to do with as we please. The Earth has mechanisms to cleanse itself, to neutralize the toxic substances in its system. But these mechanisms work|only up to a point. Beyond some critical threshold, they break down. The damage becomes irreversible. [..] The bright, sandy surface and dusty atmosphere of Mars reflect enough sunlight back to space to cool the planet freezing out all its water, locking it in a perpetual ice age.
Human activities brighten our landscape and our atmosphere.
Might this ultimately make an ice age here?

Although the specter of global cooling is indeed raised, so is the lack of scientific certainty and consensus… But what about the greenhouse effect and the state of climate science in 1980?

At the same time, we are releasing vast quantities of carbon dioxide, increasing the greenhouse effect. The Earth need not resemble Venus very closely for it to become barren and lifeless. It may not take much to destabilize the Earth’s climate to convert this heaven, our only home in the cosmos into a kind of hell. The study of the global climate, the sun’s influence, the comparison of the Earth with other worlds… These are subjects in their earliest stages of development. They are funded poorly and grudgingly. Meanwhile, we continue to load the Earth’s atmosphere with materials about whose long-term influence we are almost entirely ignorant.

As I said, no consensus. And rather than revile today’s state of climate science, for example as summarized in the IPCC reports, we should be impressed with how far we’ve come in only a few decades.

Cosmos, 1990

Already ten years after the first airing of Cosmos, climate science (as well as astronomy) had advanced considerably, and when the series was reissued in the early nineties, a brief update was appended to many episodes. Regarding climate change, a ten year older Carl Sagan now had the following to add:

Since this series was first broadcast the dangers of the increasing greenhouse effect have become much more clear. We burn fossil fuels, like coal and gas and petroleum, putting more carbon dioxide into the atmosphere and thereby heating the Earth. The hellish conditions on Venus are a reminder that this is serious business. Computer models that successfully explain the climates of other planets predict the deaths of forests, parched croplands, the flooding of coastal cities, environmental refugees, widespread disasters in the next century unless we change our ways.

Now

The surface of Venus (from Cosmos episode 4)

Just to dwell on the obvious… Sagan’s future is today’s now. We currently are experiencing many of the gloomy predictions from twenty years ago. I wrote this in NYC during a record shattering heat wave across the U.S. 71% of Texas suffers from exceptional drought, its driest period there since 1895, with heat waves raging through many southern states… The worst drought in Somalia in 60 years… One fifth of Pakistan flooded last year… Enormous floods in China and Australia as well… a monster heat wave in Russia… a drop in September arctic ice volume from 10,000 cubic km in 1980 to 4,000 cubic km now. The list goes on and on… Sagan wouldn’t mince words were he to provide another update to Cosmos!


What’s in it for me?

March 12, 2011

you maniacs!

Global temperature

The effects of global warming are visible all over the world, but not all evidently so. For example, the rise in global mean land-ocean surface temperature has been 0.6 degrees Celsius since 1980. But no one experiences the global average temperature directly -it is after all the average over a wide range of temperatures from cold Siberia to the Sahara desert, so in terms of personal experience this fact is meaningless.

One needs to know the context in order to understand what this means. This context is provided by facts such as that this change is roughly twice the global mean temperature change between 1880-1980, that the uncertainty estimate for recent data is 0.1 deg, that temperature reconstructions reveal the current temperature to be unprecedented over at least 1800 years, etc.

Single events

There already have been colossal changes and events in recent years with a clear and obvious impact. There is the incredible drop in arctic ice volume (11,000 cubic km since 1980, with only 4,000 cubic km left on average in sept. 2010, again context is needed). Or the recent flood in Pakistan that affected an area at least the size of England. And other floods, like the flash floods in North-West China (resulting in over a thousand deaths) or the big flood in Australia (which affected 200,000 people). But the link between events like floods and heat waves and global warming is a tricky one, just like the link between smoking and lung cancer in an individual patient: the increase in their occurrence is a solid prediction in a statistical sense, but the story for each individual case is complex. Last year’s heat wave in Russia is a case in point, and may to a large extent be attributable to a `normal’ weather extreme [update Mar 14, 2011: or global warming after all? See here for a compelling argument]. Besides, all this still doesn’t directly touch upon the lives of people here in America -who typically haven’t visited the Arctic recently, let alone twice and know in their hearts that countries like Pakistan don’t really exist. Even the rising global food prices, caused mainly by weather calamities and stirring up mass protests and revolt in the Arab world, such as the revolution in Egypt, have little impact in the U.S. as Americans spend a relatively small fraction of their income on food. Only when global warming and weather start to impact the rental prices here in New York I’m going to be seriously screwed.

Global warming predictions for New York

All this raises a question: what will we experience locally from the global climate change? The simple rule of thumb answer -expect more extreme weather events as the temperature erratically becomes higher and higher- is just that, a rule of thumb. It tells us that the U.S. snowstorms last winter are consistent with and expected from global warming, but the more local you look, to more complicated everything becomes. A very useful resource is the report Global Climate Change Impacts in the United States by the United States Global Change Research Program, available here.

Image from page 109 of "Global Climate Change Impacts in the United States"

When it comes to New York (or the North East coast in general), it tells us the following. First, the past:

Since 1970, the annual average temperature in the Northeast has increased by 2°F [=1.1 deg. Celsius], with winter temperatures rising twice this much. Warming has resulted in many other climate-related changes, including:

  • More frequent days with temperatures above 90°F
  • A longer growing season
  • Increased heavy precipitation
  • Less winter precipitation falling as snow and more as rain
  • Reduced snowpack
  • Earlier breakup of winter ice on lakes and rivers
  • Earlier spring snowmelt resulting in earlier peak river flows
  • Rising sea surface temperatures and sea level

Then, the future:

Over the next several decades, temperatures in the Northeast are projected to rise an additional 2.5 to 4°F in winter and 1.5 to 3.5°F in summer. By mid-century and beyond, however, today’s emissions choices would generate starkly different climate futures; the lower the emissions, the smaller the climatic changes and resulting impacts. By late this century, under a higher emissions scenario:

  • Winters in the Northeast are projected to be much shorter with fewer cold days and more precipitation.
  • The length of the winter snow season would be cut in half across northern New York, Vermont, New
    Hampshire, and Maine, and reduced to a week or two in southern parts of the region.
  • Cities that today experience few days above 100°F each summer would average 20 such days per summer, while certain cities, such as Hartford and Philadelphia, would average nearly 30 days over 100°F.
  • Short-term (one- to three-month) droughts are projected to occur as frequently as once each summer in
    the Catskill and Adirondack Mountains, and across the New England states.
  • Hot summer conditions would arrive three weeks earlier and last three weeks longer into the fall.
  • Sea level in this region is projected to rise more than the global average,

So, what’s in it for me? (sang the N.Y. Indie band the Walkmen in 2004). The bottom line, if you’re planning on doing business or living in NY, you’d better start paying attention:

The densely populated coasts of the Northeast face substantial increases in the extent and frequency of storm surge, coastal flooding, erosion, property damage, and loss of wetlands. New York state alone has more than $2.3 trillion in insured coastal property. Much of this coastline is exceptionally vulnerable to sea-level rise and related impacts. Some major insurers have withdrawn coverage from thousands of homeowners in coastal areas of the Northeast, including New York City.

Rising sea level is projected to increase the frequency and severity of damaging storm surges and flooding. Under a higher emissions scenario, what is now considered a once-in-a-century coastal flood in New York City is projected to occur at least twice as often by mid-century, and 10 times as often (or once per decade on average) by late this century. With a lower emissions scenario, today’s 100-year flood is projected to occur once every 22 years on average by late this century.


The sun wakes again

January 31, 2010


The astronomy department of the University of Amsterdam recently moved to a new building which will eventually house all science research of the UvA. One of the best things out of this is that the institute now has two brand new telescopes for educational purposes, one of which for looking at the sun. Last Monday the astronomy professor in charge of the two observation domes finished mounting the solar telescope and I took some pictures with my mobile phone of the image that it projects (it took me a while to get them off the phone and on the computer, I had some troubles with the Bluetooth settings of the phone)

The pictures show the image from the telescope as it is projected on a white screen mounted directly behind the telescope, taken on January 22nd. The white spot is the sun shining directly on the screen, the grey / yellow disc is the projection. The blurry edge around the disc is caused by the atmosphere in Amsterdam. The little black dot and the baby dots on the right in the disc are sunspots – the only visible sunspots on the entire sun! The professor was ecstatic that there was at least one proper sunspot, for he had set up an elaborate astronomy class elsewhere a week before and the students ended up disappointed because there wasn’t a single sunspot to be seen.

The sun has been extraordinarily quiescent the past years, even beyond the normal solar cycle. Which may be boring for astronomers, but from the perspective of climate science has been a relief. Although not much of a relief, for the past decade nevertheless still is the warmest decade on record. This record is likely to be broken by the following decade as the sun becomes active again. To quote p. 37 of my copy of The New Solar system (4th edition) which I bought approximately one solar cycle ago for an introductory astronomy class:

The sun becomes brighter overall as the number of sunspots on its surface increases, and vice versa. This seems counterintuitive, since sunspots are cooler than their surroundings. However, the sunspot cycle is accompanied by variations in magnetic activity, which create an increase in luminous output that exceeds the cooling effects of sunspots. Indeed, the entire spectrum of the Sun’s radiation varies in step with the 11-year cycle of solar magnetic activity.


The Copenhagen diagnosis

January 20, 2010

The big climate conference in Copenhagen last December has resulted in a disappointment. Although it can be argued that US president Obama is working very hard to address the climate issue and is making progress, Copenhagen came at a bad moment for the US administration.

Nevertheless, the stakes remain incredibly high. This becomes clear when one reads the Copenhagen Diagnosis, an update on the state of the science of global warming that has been issued by leading climate scientists, independently from the IPCC assessments that are issued every four years. Although the report has been made available already last December (obviously to coincide with the Copenhagen conference), I think it is important enough to call attention to even if I am a bit late to the party. It is freely available from www.copenhagendiagnosis.org. For the impatient, I have copied the Executive Summary below.

The most significant recent climate change findings are:

Surging greenhouse gas emissions: Global carbon dioxide emissions from fossil fuels in 2008 were 40% higher than those in 1990. Even if global emission rates are stabilized at present-day levels, just 20 more years of emissions would give a 25% probability that warming exceeds 2°C, even with zero emissions after 2030. Every year of delayed action increases the chances of exceeding 2°C warming.

Recent global temperatures demonstrate human-induced warming: Over the past 25 years temperatures have  increased at a rate of 0.19°C per decade, in very good agreement with predictions based on greenhouse gas increases. Even over the past ten years, despite a decrease in solar forcing, the trend continues to be one of warming. Natural, short-term fluctuations are occurring as usual, but there have been no significant changes in the underlying warming trend.

Acceleration of melting of ice-sheets, glaciers and ice-caps: A wide array of satellite and ice measurements now demonstrate beyond doubt that both the Greenland and Antarctic ice-sheets are losing mass at an increasing rate. Melting of glaciers and ice-caps in other parts of the world has also accelerated since 1990.

Rapid Arctic sea-ice decline: Summer-time melting of Arctic sea-ice has accelerated far beyond the expectations of climate models. The area of summertime sea-ice melt during 2007-2009 was about 40% less than the average prediction from IPCC AR4 climate models.

Current sea-level rise underestimated: Satellites show recent global average sea-level rise (3.4 mm/yr over the past 15 years) to be ~80% above past IPCC predictions. This acceleration in sea-level rise is consistent with a doubling in contribution from melting of glaciers, ice caps, and the Greenland and West-Antarctic ice-sheets.

Sea-level predictions revised: By 2100, global sea-level is likely to rise at least twice as much as projected by Working Group 1 of the IPCC AR4; for unmitigated emissions it may well exceed 1 meter. The upper limit has been estimated as ~ 2 meters sea level rise by 2100. Sea level will continue to rise for centuries after global temperatures have been stabilized, and several meters of sea level rise must be expected over the next few centuries.

Delay in action risks irreversible damage: Several vulnerable elements in the climate system (e.g. continental ice-sheets, Amazon rainforest, West African monsoon and others) could be pushed towards abrupt or irreversible change if warming continues in a business-as-usual way throughout this century. The risk of transgressing critical thresholds (“tipping points”) increases strongly with ongoing climate change. Thus waiting for higher levels of scientific certainty could mean that some tipping points will be crossed before they are recognized.

The turning point must come soon: If global warming is to be limited to a maximum of 2 °C above pre-industrial values, global emissions need to peak between 2015 and 2020 and then decline rapidly. To stabilize climate, a decarbonized global society –with near-zero emissions of CO2 and other long-lived greenhouse gases – needs to be reached well within this century. More specifically, the average annual per-capita emissions will have to shrink to well under 1 metric ton CO2 by 2050. This is 80-95% below the per-capita emissions in developed nations in 2000.

I highly recommend reading the report itself. It is only 64 pages, including clear graphs and a number of gorgeous pictures (and lots of citations of scientific papers for further reading, for those who share my luck of having internet access to peer-reviewed journals). It also very specifically addresses and debunks a number of layman arguments that have often been put forth against climate change (“CO2 increase historically trails temperature increase and therefore it still does now”, etc).

In my opinion the report is an example of scientific outreach at its best. The climate debate has become heavily politicized (the public debate, that is. Although there exists a fierce and lively scientific debate about the details, the genuinely scientific debate on the reality of man-made global warming is long over. The basics of man-made global warming have been firmly established using the same scientific principles that are found in other natural sciences, like my own field of astrophysics). Whatever climate scientists do, it will be held against them: if they don’t invest time and energy in outreach they will be painted as stuck in their ivory towers and out of touch, and if they do, they will be labelled activists. The Copenhagen diagnosis presents a very strong case that outreach from active climate scientists is crucial to the public conversation. And someone who tells a disturbing truth is not by definition an activist.