Environmental issues and natural resource depletion are great threats to world economies, what do you think?

yes is it                    .

When it is too costly to exclude some people from access to an environmental resource, the resource is either called a common property resource (when there is rivalry for the resource, such that one person's use of the resource reduces others' opportunity to use the resource

The basic problem is that if people ignore the scarcity value of the commons, they can end up expending too much effort, over harvesting a resource

Thanks for the invite I am waiting for answers to relevant experts

Yes, they are...Thanks for the invitation. 

In under developed Countries, "YES" up to a limit but in case of developing or developed Countries, "NOT"  and again it is one of benefit of globalization most of the counties have the solutions to over such threats forever.

yes it is..and to get rid of this issue one should have proper planning called forensic analysis which consider all this environmental related parameter to avoid any future delay  in projects.As we all know time is directly proportional to economy .......  

Yes, it is true, and something must be done to overcome it.