KESKUSTELU

Ja edelleen ihmettelemme sitä miksi puuston kasvuvyöhykkeet eivät ole alkaneet liikkua kohti "pohjoisempia" alueita ja nousta vuoristossa korkeammalle. Toki on huomioitava viive, nykytilanne on perua 1980-luvun tilanteesta, mutta toisaalta jos vyöhykemuutos tapahtuu se kertoo silloin vain mitä tapahtui 1980-luvulta 2010-luvulle, ei siis esim. 2010-luvun ja 2020-luvun tilannetta.

Nature Vol 466|19 August 2010 NEWS

INCREDIBLE JOURNEY
On its third of five planned flights, the HIPPO team sampled the atmosphere from the Arctic to Antarctica.
Jet reveals atmosphere’s secrets
Marathon flights test models with first pole-to-pole snapshot of trace gases.

If only they could cash in the air miles. By flying nearly 50,000 kilometres between the Arctic Ocean and the Antarctic coast and repeatedly sampling the air at a broad range of altitudes, scientists are building the most detailed profile of the atmosphere yet.
...
As it flew, the plane (formerly known as HIAPER — the High-Performance Instrumented Airborne Platform for Environmental Research) repeatedly climbed as high as 13.7 kilometres and dipped down to a nail-biting 150 metres above the ocean waves, all the while sampling more than 100 atmospheric constituents, including greenhouse gases, aerosols and a suite of natural and industrial chemicals.
...
Scientists generally have to rely on ground measurements and then use mathematical models to extrapolate upwards when they need to create a picture of the global atmosphere, says Steve Wofsy, an atmospheric researcher at Harvard University in Cambridge, Massachusetts, and the principal investigator for the US$4-million HIAPER Pole-to-Pole Observations (HIPPO) project. “That’s like studying the ocean by studying what is on the surface of the ocean,” he says. In contrast, HIPPO can help modellers to test their ability to reproduce the atmosphere in three dimensions.

Among the surprises to come out of HIPPO data are nitrous oxide concentrations that consistently seem to increase with altitude. “Yet the models all show concentrations decreasing with altitude,” says Wofsy. The implication, he adds, is that models are either not properly accounting for the transport of nitrous oxide or they are missing a source of the greenhouse gas.

The HIPPO team also found that black carbon particles originating in Asia and beyond taper off much more quickly than expected over the Pacific. Wofsy and his colleagues report that the first HIPPO flight in January 2009 found levels of black carbon that average about five times lower than predicted by an ensemble of 14 global aerosol models (J. P. Schwarz et al. Geophys. Res. Lett. doi:10.1029/2010GL044372, in the press). The models underestimated how much black carbon is being scrubbed out of the air by precipitation, says lead author Joshua Schwarz, an atmospheric scientist with the National Oceanic and Atmospheric Administration (NOAA) in Boulder.

[Wofsy] has been up in the air for a few flights and has experienced the thrill of skimming over the waves at 150 metres, watching seals on ice floes as the jet whooshes past. “We want to see penguins,” he says, “but we haven’t seen any yet.”

Sama voi toistua nyt, kun ollaan menossa kohti lämpimimpiä aikoja antropogeenisen ilmastonmuutoksen myötä kuten Vinther et al summaavat:

10,000-year temperature history A graphical representation of the mean global air temperature that results from the amalgamation of these several records, as prepared by the Intergovernmental Panel on Climate Change (Houghton et al., 1990) and presented in the accompanying figure, indicates that temperatures during the Holocene maximum were warmer than those of the past few decades for a period of time on the order of several thousand years.

Near the beginning of the current interglacial, global temperatures rose considerably about 10,000 years ago to usher in a period of time referred to as the Holocene. On the basis of temperature reconstructions derived from studies of latitudinal displacements of terrestrial vegetation (Bernabo and Webb, 1977; Wijmstra, 1978; Davis et al., 1980; Ritchie et al., 1983; Overpeck, 1985) and vertical displacements of alpine plants (Kearney and Luckman, 1983) and mountain glaciers (Hope et al., 1976; Porter and Orombelli, 1985), it has been concluded (Webb et al., 1987; COHMAP, 1988) that mean annual temperatures in the Midwestern United States were about 2 °C warmer than those of the past few decades (Bartlein et al., 1984; Webb, 1985), that summer temperatures in Europe were 2 °C warmer (Huntley and Prentice, 1988), as they also were in New Guinea (Hope et al., 1976), and that temperatures in the Alps were as much as 4 °C warmer (Porter and Orombelli, 1985; Huntley and Prentice, 1988). In the Russian Far East, temperatures are also reported to have been from 2 °C (Velitchko and Klimanov, 1990) to as much as 4-6 °C (Korotky et al., 1988) higher than they are today; while the mean annual temperature of the Kuroshio Current between 22 and 35 °N was 6 °C warmer (Taira, 1975), and the southern boundary of the Pacific boreal region was positioned 700 to 800 km north of its present location (Lutaenko, 1993).

Olemme menossa mitä ilmeisemmin hitaasti (tai pienemmällä todennäköisyyllä hieman nopeammin) kohti seuraavaa jääkautta.

Jääkausi kyllä tulee tuhansien ja tuhansien vuosien kuluttua, mutta sitä ennen saamme selviytyä itse aiheutetusta ilmastonmuutoksesta.