Observations of climate change

Global Warming is unequivocal

	Since 1970, rise in: Decrease in:
	Global surface temperatures NH Snow extent
	Tropospheric temperatures Arctic sea ice
	Global SSTs, ocean Ts Glaciers
	Global sea level Cold temperatures
	Water vapor
	Rainfall intensity
	Precipitation extratropics
	Hurricane intensity
	Drought
	Extreme high temperatures
	Heat waves

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Many observed climate anomalies can be simulated in models with specified SSTs

	Sahel drought: Hurrell et al 2004,  Giannini et al 2003, Hoerling,
	US Dust Bowl: Schubert et al. 2004, Seager et al. 2005
	Drought (US, Europe, Asia): Hoerling and Kumar 2003
	But we can not (yet) simulate the observed SSTs.

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IPCC experience on observations

	Sorting out the climate signal from the noise in inadequate observations from a changing observing system is an ongoing continual challenge
	Space-based observations are a particular challenge

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Main Issues

	The in situ data are not global and have problems
	Satellites drift in orbit and instruments degrade: the data generally do not provide a climate record.  They could.
	The satellite record is in jeopardy, especially from demanifesting several climate instruments from NPOESS.
	A baseline transfer standard is essential: in situ super sites (reference radiosonde plus network).
	Regional climate requires attention to modes of variability and model initialization

Why do we need an integrated Earth System Analysis?

	We have a lot of observations: from satellites and other remote sensing.
	The volumes are huge
	We use but a small fraction
	Most are not climate quality
	Inconsistencies exist across variables
	They do not make a climate observing system
	Reprocessing and reanalysis must be part of system

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