I figure that it will be up to me (or other swedish-speaking ETers) to find that article by Kågesson. So I'll start there.

Sweden's finest (and perhaps only) collaborative, leftist e-newspaper Synapze.se

OECD/ITF: JTRC Discussion Papers

Environmental aspects of inter-city passenger transport
Per KAGESON, Nature Associates, Stockholm, Sweden
Discussion Paper No 2009-28, December 2009

The 25% increase is nothing he shows, it is something he assumes in making the calculations, based on an Norwegian HSR-line.

And in conclusion, I'll cite Kågeson, p.25:

The conclusion of this paper is that investment in high speed rail is under most circumstances likely to reduce greenhouse gases from traffic compared to a situation when the line was not
built. The reduction, though, is small and it may take decades for it to compensate for the emissions caused by construction. However, where capacity restraints and large transport volumes justify investment in high speed rail this will not cause overall emissions to rise.

In cases where anticipated journey volumes are low it is not only difficult to justify the investment in economical terms, but it may also be hard to defend the project from an environmental point of view as it will take too long for traffic to offset the emissions caused by building the line. Under such circumstances it may be better to upgrade an existing line to accommodate for somewhat higher speeds as this would minimize emissions from construction and cut emissions from train traffic compared to high speed rail.

In order to become a fast, safe and affordable alternative to car travel, local and regional public transport is in desperate need of funding.

Yes! But it is not either/or but both/and. His views of economics might preclude doing either, but, so long as there is significant unemployment in the EU, with appropriate actions by governments and monetary authorities, the infrastructure can be built and so doing will benefit the economy during and after the construction without increasing inflation, though inflation could be caused by other factors, including increased resource costs. Unfortunately, public adherence to neo-liberal economic views will likely prevent such sane actions.

A tragic example is the terrible commuter-train accident in Belgium earlier this year. Belgium is investing millions of euro in HSR, and at the same time the safety standard of local trains has deteriorated to a point where lives are placed at risk.

So, has train travel become more dangerous in Belgium than car travel? And, again, it is not really an either/or choice unless Belgium is at full employment.  

"It is not necessary to have hope in order to persevere."

For every investment in HSR there is also an alternative use of the money. In order to become a fast, safe and affordable alternative to car travel, local and regional public transport is in desperate need of funding.

This is clean BS, and the worst kind of zero-sum thinking. In the USA, local, regional and intercity public transport is in desperate need of funding. Public transport functions best if modes for different distances and capacities, which are in effect different levels of a hierarchic system, are linked up at hubs. The accessibility via the other levels increases the utility of each mode (you get more HSR passengers with a subway link to the station resp. you get more light rail passengers with a link to a HSR station). It doesn't make sense to pick out one level of public transport, even less to make them run for the same money.

What is debatable is the ratio of funds earmarked for the different modes. However, given the severe underfunding on all public transport fronts and the hundreds of billions given to road construction, it is silly to look for a re-division of funds already earmarked for public transport rather than a re-division between road and rail.

A tragic example is the terrible commuter-train accident in Belgium earlier this year. Belgium is investing millions of euro in HSR, and at the same time the safety standard of local trains has deteriorated to a point where lives are placed at risk.

Gah. No, the safety system did not deteriorate, it was outdated and its upgrade was very sluggish.  But that doesn't mean that there was no investment at all: new trains are purchased (and already have the new Belgian safety system -- including one of the collided trains!), and Brussels's and Antwerp's suburban rail system was expanded resp. its lines were upgraded and partly quadruple-tracked in parallel with high-speed line construction.

Of course, again, Belgium could do a lot more in terms of rail investment. (In particular, more new suburban trains.)

_{*Lunatic*, n.
One whose delusions are out of fashion.}

With HSR, endpoint inhabitants in major cities will have a new alternative to travel fast and convenient from city to city. But the people in between are likely to end up with fewer train connections (high-speed trains make few stops), or no train station at all. Because of the need to make HSR-lines very straight, it is also likely that the in-between stations will be built away from city centres, surrounded by malls and shopping centres in connection to the new station. The effect of that is - as we all know - increased car dependence.

Here they touch on some real problems with some HSR projects, but assume that it can't be done another way.

• It is of course true that the number of intercity trains on old mainlines paralleling a high-speed line typically decreases. However, this doesn't always mean a quality decrease in train connections: the discontinued services on the old line are often through trains with few stops, and the number of trains on the old line with more stops can actually increase. (For example, the two stations on the old line that are bypassed by the high-speed line section opened in South Korea this past 1 November were passed by most KTX trains but now up to 12 a day and direction stop there.)
  
  The bad examples here are when a railway sets high ticket prices for a high-speed line but then fears that passengers will use the slower but cheaper alternative, and makes that service worse on purpose. You don't have to stop all HSR construction to avoid this problem...

• The author forgets about effects on other lines. In countries where normal rail and HSR have the same gauge, it is common to run high-speed trains beyond the end of high-speed lines, to cities along conventional lines, which would not justify a high-speed line in themselves (or construction is still planned). That way, service and ridership is improved on those conventional lines, too.

• The author also forgets about capacity problems, which are enhanced by the different speed of local, intercity passenger and freight trains. There are cases when high-speed rail lines have enabled enhanced local passenger train frequency (above all Japan; but also, for example, Mannheim-Stuttgart, or indeed Brussels-Leuven...)

• It is true that many secondary high-speed rail stations are built in the green. However, some of these (including the French ones) weren't meant to be built by the railway and are a bone given to local politicians; and others represent silly cost-saving, saving the cost of a not even too long tunnel under a city. Still others, typically in the Far East, are meant to foster the growth of a new city centre. In the USA, HSR stations could even serve as centres for concentrated development in place of existing sprawl.

• The author probably also missed that some of these away-from-town stations have fostered the development of local rail: after protests about bad traffic connection, a local rail line was built, which then also served other parts of the city. (Examples from the themes of my last two diaries are the subway extension also serving Cheonan-Asan station in South Korea, and the new lines in construction to Hsinchu, Taichung and Tainan stations in Taiwan.)

• The author also forgets about high-speed lines without existing parallel conventional line service. For example, Sweden's new Botniabanan, or the Jönköping-Göteborg section of its planned triangle system.

• Carbusting is one thing, but what about airplanes? I'm afraid the main alternative to HSR is not existing conventional rail, but short-range planes.

Building HSR is extremely expensive and, as a consequence, so is their ticket price. Since the HSR service started running from Paris to Brussels, there is no regular train service left on the route. Ticket prices on the HSR-line are very expensive, and so the budget traveler ends up with two options: bus or car.

There are no direct trains, but there are lots of trains on partial sections. And it was the original system in France that showed how things can be done differently: on the first high-speed line, ticket price was the same as for trains on the parallel conventional line. Then higher peak hour and lower off-peak prices were introduced as a means to limit rush-hour crowding, and advance purchase is favoured... Paris-Brussels tickets range between €44 and €82.

The author also forgets to mention the increase in the number of Thalys passengers relative to the old number of train (and plane) passengers.

_{*Lunatic*, n.
One whose delusions are out of fashion.}

at least 25 percent of the trips will be newly generated.

That's dwarfed by the energy efficiency and CO2 emission improvement for the trips replacing car and plane trips.

In the study Kågesson also concluded that one million yearly single trips on a typical 500 km line resulted in a reduction of about 9,000 tons of CO2-equivalents. That is about the same amount as the yearly personal emissions of 900 EU citizens. Considering that building the line causes millions of tons of CO2 emissions, 9,000 tons is negligible.

Considering that the line will be there for many decades at least, comparing annual CO2 savings from just one million trips with construction emissions is silly. And road building and airport building have CO2 emissions, too.

_{*Lunatic*, n.
One whose delusions are out of fashion.}

Presently, economic growth prospects everywhere are constrained by space limitations (congestion), energy limitations, and environmental limitations. If we assume a no growth world, the Carbusters article and others who make the claim that HSR doesn't deliver enough energy reduction and other benefits which justify its cost can be (though not necessarily have to be) correct. Given other transportation options, and existing travel routes, a new, competing means of moving people may not provide enough efficiency or other benefits.

But we don't live in a static world. For better or for worse, we live in a growing world where the principal obstacle to growth is figuring out how to get more benefits from ever scarcer resources.  And HSR does precisely that by allowing ever more people to travel rapidly over longer distances despite increasing constraints on energy, space, and the climate. Its another well-shaped piece to complete another round of the ongoing Tetris game of growth and urbanization.  

It is true that HSR is unlikely to lead, by itself, to lower greenhouse gas emissions and other economic benefits because people are likely to just increase their overall travel instead of merely switching modes of it.  But that is a good thing -- a benefit of HSR and not the drawback that its detractors try to claim.  HSR allows economic growth to occur that otherwise would never be able to.

To understand this point I think it is helpful consider a business case study of early American railroads. Famously, all of the major railroads in the 19th century except one are said to have relied on substantial US government assistance for operation (and which went bankrupt nonetheless). The one railroad that didn't was the Great Northern Railroad, which today, after over a century of growth and acquisitions of weaker competitors, has grown into the Burlington Northern Sante Fe Railroad (BNSF), which itself recently became super-billionaire Warren Buffet's largest acquisition. It was founded in Saint Paul, Minnesota by a Canadian named James J. Hill, who subsequently also became, for a time, the richest man in the world like Mr. Buffet is today, personally underwriting much of Great Britain's efforts in World War I as well as changing US policy on the war from neutrality to alliance with Britain. (Although a Canadian citizen, J.J. Hill was politically very involved in US politics and served as chairman of the Democratic Party in Minnesota for most of his later life.)

Unlike the other railroad barons of the age, however, James J. Hill did not view his business as principally that of transportation. Rather, he viewed himself, and built his business, upon a model of real estate development.  He bought strategic tracts of cheap, inaccessible prairie land (much of it recently surrendered by Native American Indians), as well as urban land in city centers that would benefit from increased farming, and then he built railroads to reach them, selling the land for a profit.  It didn't really matter for the Hill railroad whether or not it paid for itself -- it sometimes did but often didn't -- because the real profits of the whole enterprise were the land valuation gains from economically developing the Great Plains. (That's where the name "Empire Builder" comes from for the Chicago-Seattle line that Hill built and is now run as an Amtrak service.)

Similarly, HSR allows for economic growth that would otherwise be constrained by real scarcity in space, energy, and environmental damage. Limiting analysis to mere transportation and efficiency outcomes like the Carbusters article does misses the primary benefit that new transportation options such as HSR provide -- economic growth.

This is also true of lunch, and indeed everything. Everything has an opportunity cost.

_{It is rightly acknowledged that people of faith have no monopoly of virtue - Queen Elizabeth II}