The statements on China were later moderated by a member of the audience who mentioned that we have to be careful about the framing as the West is responsible for a good deal of the pollution in China (this is to the tune of 23%, see 3E Intelligence).

Hmmm, I just to a look at that paper -- "Who Owns China's Carbon Emissions?" (PDF) from the Tyndall Centre for Climate Change Research -- and unless I'm misreading it, I think it's not only Western countries that are "responsible" for 23% of China's carbon emissions, but all countries that import goods from China.  And looking at who the top 10 importers from China are,

US-China Trade Statistics and China's World Trade Statistics

Table 8: China's Top Export Destinations 2006 ($ billion)

Source: PRC General Administration of Customs, China's Customs Statistics
Rank	Country/Region	Volume	% Change*
1	United States	203.5	24.9
2	Hong Kong	155.4	24.8
3	Japan	91.6	9.1
4	South Korea	44.5	26.8
5	Germany	40.3	23.9
6	tde Netderlands	30.9	19.3
7	United Kingdom	24.2	27.3
8	Singapore	23.2	39.4
9	Taiwan	20.7	25.3
10	Italy	16.0	36.7
*Percent change over 2005

The paper notes that Many of the goods exported to Hong Kong from mainland China are re-exported to other countries such as the UK after value-added processes have been performed. The major destinations of Hong Kong's re-exports, besides the Chinese mainland itself, are the USA, Japan, Germany and the UK.

But even with this qualification, I still think rather than saying "Western" countries are responsible for 23% of China's CO2 emissions, perhaps it would be better to say "countries with developed industrial economies" or something along those lines.

Truth unfolds in time through a communal process.