Scandinavian Airlines (SAS) is launching an ambitious strategy to reduce total carbon dioxide emissions by 20% by 2020, despite disappointing news on its Boeing MD-80 fleet renewal plans.

SAS's new environmental target, which assumes annual passenger growth of 4%, means each airline in the group will need to halve CO2 emissions per seat by 2020.

The carrier says the strategic environmental target, will include short- and long-term activities, with emission reductions achieved equally between technological developments including alternative fuels, next-generation aircraft and engines and operational measures.

Despite the ambitious vision, the SAS Group still appears reluctant to renew its Boeing MD-80 fleet despite the current cost of fuel, claiming that the type would still be economical even if fuel prices doubled. SAS has 57 MD-80s, although about a dozen are leased.

In its newly released annual report, SAS Group says the effect of capital costs means the MD-80 is SKr5-10 million ($800,000-$1.6 million) more profitable to the carrier than newer aircraft.

Within operations, SAS, together with Swedish air navigation services provider LFV and Stockholm-Arlanda airport, plans to introduce an ECO-Descend initiative on 10 April aimed at adapting aircraft speed in situations where - traffic permitting - a pilot with the prospect of arriving ahead of schedule can slow down in cruise and descent modes.

On 8 May, SAS will introduce STAR-CDA, allowing any aircraft to conduct "light green" continuous descent approaches at Arlanda during off-peak traffic, with no technical ground-based support.

A system called Free Route Airspace Sweden is also being introduced this year, enabling aircraft flying over northern Sweden to choose their flight path.

"Eventually we aim to develop procedures and technologies to allow this at lower altitudes where there is more traffic density and our target is to do this from 6,000m [19,700ft] by 2016-2017," says LFV director Michael Standar, who adds that this is effectively a revival of the Eight States Free Route Airspace concept that was scrapped because it had proved too complex in a pan-European context.

* SAS is expected to announce "within weeks" that it will opt for Bombardier CRJ700 and CRJ900 regional jets to replace Dash 8 Q400 turboprops.

A senior source within SAS, commenting on recent rumours said: "We have the same saying in Norwegian about there being no smoke without fire." He suggested a decision would be announced by Easter.

The Q400 replacement is a priority because SAS is having to wet-lease other types to cope with a capacity shortfall after the fleet was grounded following a series of landing incidents.