1. Ein Überblick Matthias Lüdeke, PIK, RDII
Anthropogener Klimawandel: Beobachtete Trends Attributierung Projektionen
Ein Überblick
Matthias Lüdeke, PIK, RDII

2. 1. Klimawandel Paläokimatologie Klimawandel in den letzten 150 Jahren
Potentielle natürliche und anthropogene Treiber des Klimawandels
Klimamodelle
Attributierung
Prognosen und Szenarien

3. Temperatur-Proxies und atmosphärische Spurengase über die letzten 600000 Jahre
Variations of deuterium (δD; black), a proxy for local temperature, and the atmospheric concentrations of the greenhouse gases CO2 (red), CH4 (blue), and nitrous
oxide (N2O; green) derived from air trapped within ice cores from Antarctica and from recent atmospheric measurements (Petit et al., 1999; Indermühle et al., 2000; EPICA community
members, 2004; Spahni et al., 2005; Siegenthaler et al., 2005a,b). The shading indicates the last interglacial warm periods. Interglacial periods also existed prior to 450
ka, but these were apparently colder than the typical interglacials of the latest Quaternary. The length of the current interglacial is not unusual in the context of the last 650 kyr.
The stack of 57 globally distributed benthic δ18O marine records (dark grey), a proxy for global ice volume fluctuations (Lisiecki and Raymo, 2005), is displayed for comparison
with the ice core data. Downward trends in the benthic δ18O curve reflect increasing ice volumes on land. Note that the shaded vertical bars are based on the ice core age
model (EPICA community members, 2004), and that the marine record is plotted on its original time scale based on tuning to the orbital parameters (Lisiecki and Raymo, 2005).
The stars and labels indicate atmospheric concentrations at year 2000.
Im Folgenden: wenn nicht anders gekennzeichnet, aus dem
4. Assessment Report des IPCC entnommen:

4. Auslöser für den Wechsel von Glazial- und Interglazialperioden
Nächstes Glazial: Beginn frühestens in Jahren
Berger, A.L., and M.F. Loutre, 2002: An exceptionally long interglacial ahead? Science, 297, 1287–1288.

5. Multistabilität, Verstärkung des kleinen Anstoßes durch
den Milankowitsch-Zyklus
(Bsp.: Temperatur-Albedo-Rückkopplung)
MKBL, 07

6. Globale Mitteltemperatur
Annual anomalies of global land-surface air temperature (°C), 1850 to 2005, relative to the
1961 to 1990 mean for CRUTEM3 updated from Brohan et al. (2006). The smooth curves show decadal
variations (see Appendix 3.A). The black curve from CRUTEM3 is compared with those from NCDC (Smith
and Reynolds, 2005; blue), GISS (Hansen et al., 2001; red) and Lugina et al. (2005; green).

7. Trends der jährlichen Durchschnittstemeratur
Linear trend of annual temperatures for 1901 to 2005 (left; °C per century) and 1979 to 2005 (right; °C per decade). Areas in grey have insufficient data to produce
reliable trends. The minimum number of years needed to calculate a trend value is 66 years for 1901 to 2005 and 18 years for 1979 to An annual value is available
if there are 10 valid monthly temperature anomaly values. The data set used was produced by NCDC from Smith and Reynolds (2005). Trends significant at the 5% level are
indicated by white + marks.
IPCC, AR4, nach Smith and Reynolds (2005), NCDC. +: Siginfikanzlevel 5%, grau: Daten ungenügend

8. Trends im Jahresniederschlag
Trend of annual land precipitation amounts for 1901 to 2005 (top, % per century)
and 1979 to 2005 (bottom, % per decade), using the GHCN precipitation data set from NCDC. The
percentage is based on the means for the 1961 to 1990 period. Areas in grey have insufficient
data to produce reliable trends. The minimum number of years required to calculate a trend value
is 66 for 1901 to 2005 and 18 for 1979 to An annual value is complete for a given year if
all 12 monthly percentage anomaly values are present. Note the different colour bars and units in
each plot. Trends significant at the 5% level are indicated by black + marks.
IPCC, AR4, nach GHCN precipitation data set from NCDC. +: Siginfikanzlevel 5%, grau: Daten ungenügend

9. Annual averages of the global mean sea level (mm)
Annual averages of the global mean sea level (mm). The red curve shows reconstructed
sea level fields since 1870 (updated from Church and White, 2006); the blue curve shows coastal tide
gauge measurements since 1950 (from Holgate and Woodworth, 2004) and the black curve is based
on satellite altimetry (Leuliette et al., 2004). The red and blue curves are deviations from their averages
for 1961 to 1990, and the black curve is the deviation from the average of the red curve for the period
1993 to Error bars show 90% confidence intervals.

10. Estimate of the Earth’s annual and global mean energy balance
Estimate of the Earth’s annual and global mean energy balance. Over the long term, the amount of incoming solar radiation absorbed by the Earth and
atmosphere is balanced by the Earth and atmosphere releasing the same amount of outgoing longwave radiation. About half of the incoming solar radiation is absorbed by the
Earth’s surface. This energy is transferred to the atmosphere by warming the air in contact with the surface (thermals), by evapotranspiration and by longwave radiation that is
absorbed by clouds and greenhouse gases. The atmosphere in turn radiates longwave energy back to Earth as well as out to space. Source: Kiehl and Trenberth (1997).
Kiehl, J., and K. Trenberth, 1997: Earth’s annual global mean energy budget. Bull. Am. Meteorol. Soc., 78, 197–206.

11. Reconstructions of the total solar irradiance time series starting as
early as The upper envelope of the shaded regions shows irradiance variations
arising from the 11-year activity cycle. The lower envelope is the total irradiance
reconstructed by Lean (2000), in which the long-term trend was inferred from
brightness changes in Sun-like stars. In comparison, the recent reconstruction of Y.
Wang et al. (2005) is based on solar considerations alone, using a flux transport model
to simulate the long-term evolution of the closed flux that generates bright faculae.

12. Visible (wavelength 0.55 μm) optical depth estimates of stratospheric sulphate
aerosols formed in the aftermath of explosive volcanic eruptions that occurred between 1860 and
2000. Results are shown from two different data sets that have been used in recent climate model
integrations. Note that the Ammann et al. (2003) data begins in 1890.

13. Albedo-Effekt von Aerosolen

14. Recent CO2 concentrations and emissions. (a) CO2 concentrations
(monthly averages) measured by continuous analysers over the period 1970 to
2005 from Mauna Loa, Hawaii (19°N, black; Keeling and Whorf, 2005) and Baring
Head, New Zealand (41°S, blue; following techniques by Manning et al., 1997). Due
to the larger amount of terrestrial biosphere in the NH, seasonal cycles in CO2 are
larger there than in the SH. In the lower right of the panel, atmospheric oxygen (O2)
measurements from flask samples are shown from Alert, Canada (82°N, pink) and
Cape Grim, Australia (41°S, cyan) (Manning and Keeling, 2006). The O2 concentration
is measured as ‘per meg’ deviations in the O2/N2 ratio from an arbitrary reference,
analogous to the ‘per mil’ unit typically used in stable isotope work, but where
the ratio is multiplied by 106 instead of 103 because much smaller changes are
measured. (b) Annual global CO2 emissions from fossil fuel burning and cement
manufacture in GtC yr–1 (black) through 2005, using data from the CDIAC website
(Marland et al, 2006) to Emissions data for 2004 and 2005 are extrapolated
from CDIAC using data from the BP Statistical Review of World Energy (BP, 2006).
Land use emissions are not shown; these are estimated to be between 0.5 and 2.7
GtC yr–1 for the 1990s (Table 7.2). Annual averages of the 13C/12C ratio measured in
atmospheric CO2 at Mauna Loa from 1981 to 2002 (red) are also shown (Keeling et
al, 2005). The isotope data are expressed as δ13C(CO2) ‰ (per mil) deviation from a
calibration standard. Note that this scale is inverted to improve clarity.

15. The global carbon cycle for the 1990s, showing the main annual fluxes in GtC yr–1: pre-industrial ‘natural’ fluxes in black and ‘anthropogenic’ fluxes in red
(modified from Sarmiento and Gruber, 2006, with changes in pool sizes from Sabine et al., 2004a). The net terrestrial loss of –39 GtC is inferred from cumulative fossil fuel
emissions minus atmospheric increase minus ocean storage. The loss of –140 GtC from the ‘vegetation, soil and detritus’ compartment represents the cumulative emissions
from land use change (Houghton, 2003), and requires a terrestrial biosphere sink of 101 GtC (in Sabine et al., given only as ranges of –140 to –80 GtC and 61 to 141 GtC,
respectively; other uncertainties given in their Table 1). Net anthropogenic exchanges with the atmosphere are from Column 5 ‘AR4’ in Table 7.1. Gross fluxes generally have
uncertainties of more than ±20% but fractional amounts have been retained to achieve overall balance when including estimates in fractions of GtC yr–1 for riverine transport,
weathering, deep ocean burial, etc. ‘GPP’ is annual gross (terrestrial) primary production. Atmospheric carbon content and all cumulative fluxes since 1750 are as of end 1994.

16. Radiative forcing is the change in the net, downward minus upward, irradiance (expressed in W m–2) at the tropopause due to a change in an external driver of climate change, such as, for example, a change in the concentration of carbon dioxide or the output of the Sun. Radiative forcing is computed with all tropospheric properties held fixed at their unperturbed values, and after allowing for stratospheric temperatures, if perturbed, to readjust to radiative-dynamical equilibrium. Radiative forcing is called instantaneous if no change in stratospheric temperature is accounted for. For the purposes of this report, radiative forcing is further defined as the change relative to the year 1750 and, unless otherwise noted, refers to a global and annual average value.
Radiative forcing is not to be confused with cloud radiative forcing, a similar terminology for describing an unrelated measure of the impact of clouds on the irradiance at the top of the atmosphere.