Sustainability is a very important topic for me. However, I don't have the impression that many people think a lot about a sustainable lifestyle and why it might be important. Year after year experts warn about the development which is taking place, but they don't seem to get heard. I want to emphasize the importance of a basic awareness of what impact our lifestyle has on the planet and the future of humankind.
Why you should bother
This is very important: Humans have abolutely no relevance in this universe. We barely have any impact on anything what's beyond earth and literally none on anything what's beyond our solar system. Any hypothetical life form living in alpha centauri (the closest solar system to our own) would probably not notice us. The universe will continue to be long after humankind got extinct. We tend to see ourselves as the most important thing in the universe (many religions communicate this lesson), but this is not true. Don't take yourselves too important; no higher cosmic power will prevent us from destroying ourselves.
On earth however, we have a tremendous impact on our environment. Beginning with forming the surface, building houses, cities, artificial riverbeds, you name it. The list continues with usage of earth's resources to our advantage. This is not a problem, as long as we do it sustainably.
The thing is, if we don't use our resources sustainable, we're continuing to navigate into a situation where we can no longer maintain the lifestyle we're living now. May it be since we used up too many non-renewable resources, we destroyed climate, leading to frequent catastrophes or since we just became too many people that all demand a prosperous lifestyle.
Earth has outlived much worse disasters than humans, it will be able to survive.
However, we are not protecting the universe, not the planet and not trees with a sustainable lifestyle. We are protecting humankind itself.
Developing towards a more sustainable lifestyle does not mean living ascetic. I'm a huge fan of the pareto principle which basically says, 80 % of the effects come from 20 % of the causes. For example, if you clean up your house, it takes you 20 minutes to clean up 80 % of the mess. However, it will take you 60 minutes to clean up 95 % and 3 hours to clean up 100 % of the house. This principle makes a statement on what's the best price/performance ratio in almost any domain. I'm living this principle to the fullest extend and it can also be applied to a sustainable lifestyle. Find your 20 % that have an impact of 80 %.
To measure sustainability, one can use the ecological footprint. It is measured in units of global hectars (gha) and depicts how much average land one person with a certain lifestyle would need to maintain her lifestyle. For a truly sustainable lifestyle, one would need 1.7 gha, but we're far away from that. The world-wide average is 2.8 gha, in Germany 5.3 gha and in the USA 8.2 gha [source]. We're living a life on credit with no intend to ever pay anything back.
What actions to take
In the following, I will point out some aspects that can lower your ecological footprint with few efforts.
Food has a huge impact on your ecological footprint. Seas are overfished, animals are hormone treated to deliver as much meat as possible in a short amout of time. For the production of 1 kg beef, it takes over 15.000 litres of trinking water and over 6 kg of crop and 330 m2 ground [source]. As you see, animals have a terrible efficiency in converting one kind of food into another. For feeding the tremendous masses of fatstock we need to statisfy our demand for meat and animal products, we are burning down forests to be able to grow insane amounts of monocultures like soy. We could feed a lot people with this food, but instead we're converting it into food of animal origin which can just feed a fraction of people.
I think the easiest opportunity to lower your ecological footprint is to eat less meat. For instance, if you haven't been aware yet, try to only eat meat twice a week. This already has a great impact while you don't have to miss that delicious steak you love so much. Further, being completely vegetarien or even vegan helps even more, of course.
Another aspect is to buy food depending on origin and season. If some fruits don't grow (the whole year) in your country, obviously they have been transported there. Some food is transported around the whole globe to be sold, which means a huge stress for the environment. If possible, try to shop food which is created locally. If you watch out for organic food you can support better treatment of animals, usage of less toxic substances and avoidance of monocultures which threaten biodiversity.
Finally, try only to buy what you actually are able to eat. Throwing away food is similarily bad for your ecological footprint.
Mobility is a fundamental need for people. Today, most own a car to get around, and it should not be new to you that this is also one of the worst ways to move from a sustainable point of view. Combustion engine cars emit greenhouse gases, particulate matter and nitrogene oxide, to name a few. Those emissions speed up the climate change and cause heavy diseases like cancer or strokes [source]. In Germany, transport is responsible for about 15-20 % of the total greenhouse gas emissions per year. This number is high enough to be worth to think about.
In urban areas it is unattractive to own a car already. Parking space is limited, traffic jams are usual. Most times, people would be faster with public transport or bicycles. This would lead to less stressful traffic, fewer noise, fewer emissions and fewer threats due to cars, cyclists and pedestrians operating on a tight space.
While in rural areas it is often hard to avoid a car, it is possible. I haven't owned a car in my almost 30 years of life and currently I'm living in a small town in Germany. Most people around me own cars and I would be lying to state that it would not make a difference comfort-wise. However, I also love cycling and therefore use my bicycle 99 % of the time to get around. For far distances, I take the train or bus. For those 2 months a year, when it's raining and cold, I got to grit my teeth (and think of all the money I'm saving and all the good I'm doing for the climate). I think most people don't gear up adequately to ride their bikes through winter. Buy a high quality, waterproof jacket and pants along a good bicycle and while you still save a lot in comparison to a car, you will stay warm and dry as well. Lastly, your fitness will greatly benefit from your low-intensity everyday workouts and riding your bike literally does not add anything to your ecological footprint.
If for some reason a bicycle is not an option, try to take public transport. Many of it still runs on fossil fuels, but the efficiency per person is much better than in a one-person-per-car situation.
Another alternative are non-feul driven vehicles like electric scooters or cars. I'm a great fan of electromobility, since it does not produce any local emissions. If you keep your eyes open, you are able to charge your electric vehicle (EV) with fully renewable energy sources, leading to literally no emissions. On the other hand, EVs don't solve the problem of too many cars in our cities, traffic jams and dangers in traffic. EVs are still very expensive and not subsidized enough by the government. Loading infrastructure in Germany is poor, not because there would not be any charging points, but they are poorly maintained, often broken and the billing system is ridicolous. You have to have a contract with a supplier before you can use their charging points and billing is often done by time or across-the-board instead of per kWh. Imaging going to a gas station, being asked to become a customer first and then pay 50 EUR no matter how much feul you actually filled up. If you have the opportunity to charge at home (most people won't), and you want to be an early adopter, an EV might be an option.
Again, apply the pareto principle here. If you don't want to resign from any habits, try to establish one or two days a week when you take the bicycle.
As you can see in the graphic above, energy industries are responsible for about 30 % of greenhouse emissions in Germany. If you can afford it, get yourself a power supplier with green energy. Turn of devices if you don't use them. This does not mean to put yourself back into medieval ages. With todays' smart home technology, you can use smart plugs to switch devices on and off just with your voice. Modern technology and energy saving is not a contradiction.
Take five minutes of your time to go through your apartment and identify devices that don't need to be powered on 24/7. Not only is it more sustainable, but you will also thank yourself when the energy bill is due.
There are much more areas where sustainability can be established, for instance consumerism, clothing and cosmetics. I haven't dealt with these topics in detail but feel free to inform yourself. I hope I could help you to understand the importance of a sustainable lifestyle and to point out that it does not take much effort to take actions that already have a great impact.