The chartered body for landscape architects said a decrease in emissions of at least 80 per cent by 2050 should be achieved - and not just the 60 per cent target (against 1990 levels) published by Parliament on 15 November in its Climate Change Bill.
LI Policy Committee chairman Jon Lovell said: "We welcome the bill, but we believe that there is sufficient credible evidence to suggest that the 60 per cent target is inadequate and should be increased to at least 80 per cent now and not wait for the proposed climate change committee to report on the matter in 2009. Indeed, 80 per cent should be the very minimum target for the Government."
The bill, hailed by the Government as "landmark legislation" for being the first bill of its kind in the world, also set out plans for a new committee on climate change to give expert advice on the issue.
Lovell said the landscape architecture profession should be represented on this committee as it provides a vital service in dealing with climate change.
"The holistic approach of landscape architecture to place-shaping means that landscape architects know how to adapt our towns, cities and countryside to the changing climate and, given the importance of the landscape architecture profession in the fight against climate change, we would call for representation on the climate change committee.
"Whatever we do as a nation to deal with this crisis must be supported by the expertise of professionals who understand the living environment at every scale from the local neighbourhood to the regional landscape."
A recent survey of LI members showed that 73 per cent of landscape architects have successfully influenced clients to consider climate change issues.
In addition, work done by landscape architects in Boscastle, Cornwall, after the town suffered flooding in 2004, prevented a repeat this summer.
The issue of climate change was addressed at the LI's annual conference earlier this month when DEFRA secretary Hilary Benn acknowledged that landscape architects played a crucial role in tackling climate change and spoke of the need to devote more time and energy to green infrastructure.