There’s this old joke about vegans. How do you spot a vegan at a dinner party? "Don’t worry, they’ll tell you," goes the answer.Most of us have been on the receiving end of a diatribe about the environmental impact of meat production, about how meat isn't just murder, but greener is actually cleaner. The opinion seems to be growing in popularity: Less and less, environmentally-conscious veganism isn’t something we cynically deride, but something we celebrate.This is because our generation is truly beginning to accept the reality that climate change is happening, and that it’s probably going to affect us, and our children. According to the UN’s most recent report, Climate Change 2014 , the “severe and pervasive” impacts of climate change will be felt globally in our lifetimes. Sea levels are rising; deforestation means that food insecurity is increasing, and entire species are at risk of extinction. Things aren't looking good.Leonardo DiCaprio even used his Oscar acceptance speech to share his concerns. "Climate change is real," said the actor. "It is happening right now, it is the most urgent threat facing our entire species and we need to work collectively and stop procrastinating. We need to support leaders around the world... who speak for all of humanity."While all of humanity ought to agree that becoming more sustainable in your everyday life is a good thing, sometimes it’s difficult to know where to start. We’re all busy, we’re often broke and exhausted, and the last thing you want when you can barely find time to wash your hair is to introduce a huge lifestyle change that’s just going to leave you with even less of your precious time.That said, you don’t need to sacrifice huge amounts of time, effort or money to become more sustainable. There are small changes you can make to your everyday routine that will not only cut on wastage, environmental damage and fossil fuel emissions, but save you money in the process. So scroll through the following slideshow for some top tips to becoming more sustainable – without becoming the sort of person everyone avoids at dinner parties.