It's a poorly done paper and therefore doesn't help much as far as addressing this issue. But I suspect if a more rigorous paper was written on the topic, it would point to out that rather than the risks possible higher global temperatures, rising CO2 [of a significant amount] pose serious health risks in terms quality of life.

Considering a how crazy Americans are about their health, it's strange that people don't generally measure the CO2 levels in their homes and where they work. I would bet that at this moment millions of people are affected by having too high a level of CO2 in their environment.

I don't have a CO2 detector, but I have gone to many buildings with poor ventilation- and at least it has psychological affects, but it seems in general to wear you out. Why do people who [btw] need air, place so little concern over having sufficient ventilation?
Much concern about banning cigarettes, but if cigarette smoke is a problem, then in same situation indicates that lack of air circulation is a more serious problem. For example in bar with what looks like thick inversion layer of cigarette smoke, obviously isn't getting enough air flow to deal with high numbers of people or even fewer people over longer periods of time.

But there isn't much awareness about CO2 in regard to breathing it- we all know from space activity that the problem isn't a lack of oxygen but the increasing levels of CO2.

Here is example of the clueless:

"You can’t see it. You can’t smell it. You can’t taste or feel it. It enters your body with every breath and you don’t even know it. Carbon dioxide (CO2) has no direct effect on people.
...
Computer models are not perfect. But they have been the only way to study the effects of CO2 in the atmosphere.

Until now.
In 1998, Idso discovered that Phoenix lies under a carbon dioxide “dome.” The city has CO2 levels up to 50 percent higher than the global average.

Those high levels are what scientists expect to see around the world in about 50 years. Because Phoenix is ahead of the game, scientists can use the city as a natural “laboratory” to study the effects of these changes."
http://chainreaction.asu.edu/ecology/digin/carbondioxide.htm

Yeah, like Phoenix is special and we have new "discovery". Sure this stupid article written by some idiot, but also indicates a baseline of idiocy which is rampant

This is what wiki says:
"It is dangerous when inhaled in high concentrations (greater than 5% by volume, or 50,000 ppm). The current threshold limit value (TLV) or maximum level that is considered safe for healthy adults for an eight-hour work day is 0.5% (5,000 ppm). The maximum safe level for infants, children, the elderly and individuals with cardio-pulmonary health issues is significantly less.

These figures are valid for pure carbon dioxide. In indoor spaces occupied by people the carbon dioxide concentration will reach higher levels than in pure outdoor air. Concentrations higher than 1,000 ppm will cause discomfort in more than 20% of occupants, and the discomfort will increase with increasing CO2 concentration. The discomfort will be caused by various gases coming from human respiration and perspiration, and not by CO2 itself. At 2,000 ppm the majority of occupants will feel a significant degree of discomfort, and many will develop nausea and headaches. The CO2 concentration between 300 and 2,500 ppm is used as an indicator of indoor air quality."
http://en.wikipedia.org/wiki/Carbon_dioxide

Ok, so most common cause of high level of CO2 levels is humans breathing. "Everyone knows" and for a century they have known that CO2 levels varying wildly depending upon where and when of a location. If you have increase in global CO2, that means in urban areas one will have even higher levels of CO2, which means that in a building with poor ventilation with one of people in it, one gets even higher levels. Only unique situation are you going to get levels as high as 50,000 ppm, but there also the situation of making these unique situation more common if one starts from a higher base line- though still rare. Less rare is situation where you get say 2000 ppm and by increasing the baseline level one will make these situation less rare- this probably has biggest effect in terms of health problems- making say 10 million people have headaches and feeling sick who wouldn't otherwise have this discomfort is pretty serious [especially considering almost completely ignored]. But in terms importance probably making billion people feel tired [somewhere around 1000 ppm] 1/2 or more of their lives is more significant in terms of "quality of life" and consequences of all these people basically performing somewhat at sub-human levels.