Climate Sense

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tation plan. ESA’s response took the form of a proposal for a new

programme, referred to as the ESA Climate Change Initiative, which

aims to: “Systematically generate, preserve and give access to long-

term data sets of the ECVs required to meet the needs of the parties to

the UNFCCC”. The programme was submitted to the ESA Ministerial

Council in November 2008 and accepted by ESA Member States with

a level of funding equalling EUR75 million over six years.

The programme also provided ESA with a unique opportunity

to capitalize on the huge European investment in the space sector

that has taken place over the last thirty years, and in particular

to realize the full potential of the long-term Earth observation

archives established in Europe. For example, the 15-year homo-

geneous record of high precision altimetric data from ERS,

Envisat, TOPEX/Poseidon and Jason-1 established by ESA and the

European member states provides a significant contribution to the

ECV oceanic record. Such high-quality data records have radically

transformed our view of the ocean, not only providing consider-

able insight into new and often unexpected oceanic processes, but

also by revealing the global rise of sea-level within the astonishing

accuracy of a few millimetres.

Likewise, rapid changes have been observed in the cryosphere – the

Earth’s ice and snowmasses. This comprises not only the Arctic sea ice

– which is dramatically shrinking, as observed by the Envisat mission

– but also measurements of the changes in the Greenland glaciers.

Tandem campaigns flown by the ESA flagship missions ERS-2 and

Envisat in 2008 and 2009 collected interferometry data over the Arctic

and Antarctica. They obtained important data including measurements

suggesting that the polar glaciers are moving faster than previously

anticipated. Another topic of importance is the measurement of global

deforestation rates. This supports the implementation of

the UNFCCC/REDD initiative, as such measurements will

be undertaken by the ESA Sentinel-2 mission, which is

currently under development.

The ESA Climate Change Initiative aims to provide

the necessary climate records by ensuring that the full

capital is derived from data obtained from ongoing and

planned missions in Europe. In particular, it is worth

noting that the SMOS mission will provide a significant

contribution to the GCOS implementation plan as it

addresses two of the highest priority ECVs: soil mois-

ture and ocean surface salinity.

Regarding direct activity, the Climate Change

Initiative aims to implement a coherent and continuous

suite of actions encompassing all the steps necessary for

the systematic generation of relevant ECVs, including

recalibration, periodic reprocessing of the long-term

records, algorithm development, product genera-

tion and validation, and quality assessment of climate

records in the context of climate models. The need for

long-term data preservation poses specific challenges.

ESA has already observed an exponential growth of its

EO data archives, with a total of some 3,300 terabytes

of data archived since 1986. It is necessary to constantly

update archiving technology, with ESA still attempting

to address the issue of establishing long-term funding

for this process. ESA plans to make a proposal to its

Member States for long-term archive maintenance at

the 2011 ESA Ministerial Conference.

Another interesting aspect of the Climate Change

Initiative lies in the set-up of a ‘feedback loop’ mechanism,

whereby new user feedback and the latest scientific knowl-

edge can be easily integrated within each re-processing

phase. This ensures regular updating of the climate records

on timescales corresponding to the increasingly urgent

needs of the international climate change community.

The Climate Change Initiative is being implemented by

ESA in partnership with key users (including GCOS and

UNFCCC), space agencies and CEOS, relevant players in

the field of climate change research (including European

Commission and the National Climate Programme) and

monitoring (including WMO, the National Oceanic and

Atmospheric Administration and EUMETSAT), as well

as in full coordination with existing activities, such as

the WMO Space Programme GSICS. A scientific advisory

group, involving world-leading scientists representing

key stakeholder organizations, has also been set up to

provide scientific guidance for the programme.

Through its Earth observation missions – in conjunc-

tionwith the Climate Change Initiative–ESA is developing

quality climate observation systems, providing free access

to the worldwide science community, and working with its

partners to ensure long-term observations of fundamental

climate data records and the resulting ECVs. The particu-

lar value of the Climate Change Initiative is that it enables

timely action from decision makers, as well as providing a

framework that will strengthen the dialogue between Earth

observation data research communities and the climate

science and modelling community.

Ozone hole during 7 October 2008

Ozone hole during 7 October 2008 as measured by the Scanning Imaging

Absorption Spectrometer for Atmospheric Cartography (SCIAMACHY)

atmospheric sensor onboard ESA’s Envisat

Source: ESA