Klimaatverandering IPCC (2013) Rob van Dorland Springtij, Terschelling 25 september 2015

Intergovernmental Panel on Climate Change, 2013

•  Detection observation

•  Attribution cause-effect

•  Projection future

Greenhouse gases

•  Concentrations now far exceed pre-industrial values spanning many thousands of years •  The increase of concentrations of CO2, CH4 and N2O are primarily due to human activities

IPCC, 2007

Global mean temperature change

Figure SPM.1

“Each of the past 3 decades has been the warmest since 1850”

Radiative Balance of the Climate System

Incoming Solar Radiation 341 Wm-2

Reflected Solar Radiation 102 Wm-2 (about 30%)

Outgoing Infrared Radiation 239 Wm-2

Changes in the Radiative Balance

Incoming Solar Radiation 341 Wm-2 +/- Δ

Reflected Solar Radiation 102 Wm-2 +/- Δ

Outgoing Infrared Radiation 239 Wm-2 +/- Δ

Radiative Forcing 1750-2011

The climate system “strikes back” by changing its temperature to compensate for the radiative forcing, but not immediately due to the heat capacity of the oceans. Therefore, radiative imbalances point towards the direction of change

Energy inventory

Box 3.1, Figure 1

93% of the energy input in the climate system has been used to warm the oceans (high confidence) 3% has been used to warm the continents 3% has been used to melt ice (glaciers, icecaps) 1% has been used to warm the atmosphere

Climate sensitivity

Global temperature change due to a doubling of CO2

From observations and models [IPCC, 2013]: •  Likely (66%) range:

1.5 – 4.5ºC •  Extremely unlikely (5%)

< 1ºC •  Very unlikely (10%)

> 6ºC

Observations and Climate Models

It is extremely likely that human influence has been the dominant cause of the observed warming since the mid-20th century [IPCC, 2013]

Attributable warming trends 1951-2011

Carbon emissions for four RCPs

Figure SPM.7, IPCC,2013

Global temperature change (rt 1961-2000)

2.6  to  4.8°C  

0.3  to  1.7°C  

Increase of global mean surface temperatures for 2081–2100 relative to 1986–2005 is projected to likely be …. 0.3°C to 1.7°C (RCP2.6), 1.1°C to 2.6°C (RCP4.5), 1.4°C to 3.1°C (RCP6.0), 2.6°C to 4.8°C (RCP8.5).

Temperature projections

Cumulative total CO2 emissions versus global mean temperature change

•  Opwarming veroorzaakt vele meetbare klimaatveranderingen

•  We begrijpen de natuurkundige werking van het systeem Aarde (inclusief de onzekerheden)

•  Grootste deel waargenomen opwarming sinds 1950 veroorzaakt door toename van broeikasgassen (>95%)

•  Bijdrage van natuurlijke factoren aan waargenomen temperatuurtrend sinds 1950 is praktisch nul

•  Zonder maatregelen stijgt de mondiale temperatuur met 3,2 tot 5,4°C (einde 21e eeuw t.o.v. pre-industrieel)

Hoofdlijnen IPCC, 2013

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