Answer:
As per Newton's 2nd law we know that
F = ma
so more mass is carried by the climber then it will need more efforts to hold it as force due to gravity on them will be more
Step-by-step explanation:
As we know that the gravitational force on an object due to earth is given as

now we know that the force applied by the mountain climber will be more to counter balance the weight of all the pack if he carry more mass with him.
So as per Newton's 2nd law if he need more mass with him then the efforts by him will be more to carry them all to a certain height.
Now before reaching summit if storm blows in then the air drag will also resist the motion of the climber and this will also increase his efforts