Should we use GMO trees to slow climate change?

After 10 seconds of googling it seems that the gene they are talking about comes into effect when plants are experiencing stress and particularly regarding water conservation  as the plant closes its leaf pores during photorespiration. 

With absolutely no in depth knowledge I am suspicious that these trees may be more susceptible to environmental stress, possibly requiring more water to thrive, or be more susceptible to pest and diseases if they cannot withstand stress as well. This might actually offset or even outweigh any positive effects.

It is very much worth looking into, because there might be something there, but this is the classic ‘scientific’ thing of not understanding a mechanism of action of something, and dismissing it without the appropriate knowledge.