What are the global effects of the loss of the siberian tiger?

In my opinion, there are no global effects or at least
none that we can really understand or quantify.

When a
species of animal goes extinct, it rarely has any effect on people, per se (unless they
rely on it for food or to keep an ecosystem in balance).  The only real impact of
extinction is on the other animals (and even plants) in the ecosystem.  You could say
that tiger extinction could lead to a boom in deer which would then affect the forests. 
But the loss of tigers is being caused by deforestation anyway -- whole ecosystems being
destroyed.  So it's not as if the ecosystem will still be there but be imbalanced by the
loss of the top predator.

What does have a global effect,
in my opinion, is the habitat loss that leads to the extinctions.  The loss of whole
habitats can affect weather patterns on a regional or even global level.  It can also
impact people (potentially) through the loss of biodiversity and through the loss of
organisms that might be beneficial to people.  However, even these impacts are hard to
distinguish since the planet as a whole is such a complex
system.