To set the stage, high intense animal farming is producing around 15% of all greenhouse gases, to produce one pound of beef it requires 2000 gallons (7600 liters) of water, animal agriculture has caused 80% of the Amazon rainforest to be cut down; as can been seen, animal agriculture is not eco friendly.
We should not eliminate our animal production, but to significantly reduce it so that it does not make as much as an impact on our environment. In order to reduce our animal production, we must send a message to those who are in charge. By going vegan or vegetarian, one is lower the demand for animal products and sending a hidden message towards animal producers; saying they don't treat animals properly and are making too many.
Conclusion: Using or eating animal products should be done only when necessary and not when wanted.
How it saves money: Meat and animal products tend to be more expensive than vegan products.