It actually doesn't dismiss a Warming Climate.
The reason why the past 100 years were removed (or considered 'bogus') were because the measuring tools (proxies: are indirect measuring tools for temperature) used were more focused on long term temperatures, too few proxies were available for 20th Century dating and the cores (which are a part of the proxies) were re-dated (by assuming they went up to the present).
Direct temperature readings were conducted since the beginning of the 20th Century that could account for short-term fluctuations and temperature readings (ex: Every Month). Applying this data with the proxies used, which show a more long term indirect temperature readings (ex: 200-300 years). These two forms of measurement are not exactly compatible and should not be combined into a single graph.
Does this mean that the current temperature changes in the past 100 years should be ignored?
No, as they clearly show more direct short-term and accurate global temperature readings (having thousands of measuring stations across the world) versus the proxies that only show an average/mean of the temperatures over longer periods and fewer locations.
Did the researcher screw up? Yes
Does that mean that everything we know about Climate Science is now wrong? No
I'm currently not able to acquire the exact research paper to inspect myself, so I'm basing my points from what I have read so far.
Some references:
http://opinion.financialpost.com/2013/0 ... t-screwed/
http://www.realclimate.org/index.php/ar ... ott-et-al/
Edit: Found the Paper in PDF format http://xa.yimg.com/kq/groups/18383638/1 ... 98-201.pdf
If this doesn't work, let me know and I'll upload it.