While I don't disagree with the environmental concerns, ships use HFO (a very dirty type of fuel that's essentially tar) and account for ~3% of all greenhouse g

While I don't disagree with the environmental concerns, ships use HFO (a very dirty type of fuel that's essentially tar) and account for ~3% of all greenhouse gasses. It may be a net win overall if a proper canal can save many more ships thousands of miles of emissions per trip. The Caribbean is facing seal level rise anyway if we don't find a way to reduce emissions. Again I'm not an expert on this subject, but it doesn't seem cut and dry that a canal would be an environmental disaster if it were possible to excavate.