Boris is not going to even attempt to achieve that, or anything like it.Actually I'd suggest that ours and every other major economy needs to contract, not move forward. Anything else is simply feeding the climate and ecological crisis.
There is a well documented straight line correlation between GDP and energy use. We cannot cut our emissions without cutting our energy use. That means shrinking the economy: decimate food wastage, insulate ALL our housing stock to cut our heating energy use by 75%+, cut our travelling etc, etc.
Enact a proper environment act and regulator able to ensure that the true environmental cost is paid at the point of use for everything we do (so we actually pay for the Chinese emissions and resource use involved in our cheap imported goods). Rebuild our soil health, ecological diversity and water cycle efficiency.
Ditch GDP as a measure of progress in favour of resource efficiency and ecological impact.
I think that's probably a bit much even for Boris to achieve but such fundamental change would need a large majority to implement and we, the public, will never vote for the pain involved. We will just keep putting it off until our world collapses round our ears.
Climate change is as much of a priority for him as it is for his mate, Trump.