Is lord Stern correct?

Comments on Nicholas Stern "Lord Stern suggests new way out of Copenhagen deadlock", 22/09/2009, http://www.telegraph.co.uk/earth/earthcomment/6215391/Lord-Stern-suggests-new-way-out-of-Copenhagen-deadlock.html

I seem to have been confused by the lord's figures. On the one hand, he is saying that "we need to reduce annual worldwide emissions from the present level of about 50 gigatonnes of carbon-dioxide-equivalent to no more than 20 gigatonnes by 2050."

On the other, he is saying "If we only reach the upper end of this range, much bigger annual reductions in emissions would be required in subsequent years, and cuts of more than 50 per cent by 2050 compared with 1990 to prevent a rise of more than 2˚C."

So isn't it from 50 to 20 more than 50% already? Or the present level of emissions are below that of 1990? Or have I got my understanding wrong?

If the lord is wrong on these figures, then couldn't he be wrong on his argument on climate change altogether?

Secondly, the lord says that "Developing countries, including China and India, also need to limit and decrease their emissions, but in ways that are consistent with their ambitions for continued economic growth and the reduction of poverty." Does that mean the current level of emissions in developing countries already exceeds the proposed level per capita by 2050? I doubt it be correct.