Is walking good for losing weight?

So I just started walking… 16 year old 125kg.
Wore comfortable clothes, had my iphone for music and a water bottle walked for 45mins (do 45mins everyday), is that good enough for losing weight if I do it every week? And I broke my arm a few months ago so can't really do much. After walking what light exercise can I do that won't involve my arm for now?

15-20 mins burns 100 cals. Do one hours walking and you could burn quite a bit.
I prefer mountain climbing

It's great that you're getting out there and doing exercise and this will help improve your physical and mental well being but on its own it won't be enough to help you lose any significant amount of weight. Say you were to burn 300 calories each time you went out for a walk, and you did this four times a week, you would burn a total of 1200 calories.

Now given that one kilogram of fat contains 9000 calories, it would take over seven weeks to lose a kilo of bodyweight! Many people believe that exercise is the main way to lose weight but this is just not true unless you are doing significant amounts. The most effective way to lose weight is to understand and manage your dietary intake.