If Russia implements its threats, it will certainly cause a global crisis, including the insane rise in the price of gas from other producers due to the increased demand .
It would be a European Crisis not a global one, worse case scenario is that the rest of the world would feel some pressure and some may even start economic expansion with negative inflation rate. It may not even be the whole Europe, for example countries like Germany, Finland and Sweden are felling the crisis a lot more than some others in the western Europe.
Increased demand for gas will raise its price worldwide. If Russia stops supplying Europe with gas, it will not find a substitute for the European market so that the price remains at reasonable levels.
The media presents that Europe can compensate for the shortfall resulting from the suspension of supplies from the Nord Stream 1 line, but no one knows for how long. I'm sure it will be a very cold winter in Europe this year.