"Houston is just a dress rehearsal for what's to come when the sea level rises, as it is guaranteed to in the next 85 years." 
Sea level has been rising since the start of this interglacial period ,about 10000 years ago. Remember ,the original inhabitants of N.A. walked here from Russia to Alaska. see: www.cabrillo.edu/~crsmith/bering.html
" (Nearly two metres is the optimistic scientific guess.)" what ,it could be worse?..lol. " Imagine the chaos when Houston and Miami and New York and Boston and Toronto and Vancouver are underwater at the same time."
Must be news to the writer ,but Toronto does not sit on any sea..lol.
What nonsense ,for the current rate of sea level rise see: https://tidesandcurrents.noaa.gov/sltrends/sltrends.html
Check the cities mentioned and compare it to the claim made.