How our consumption today affects the lives of future generations.

Our human consumption behavior contributes immensely to environmental pollution and thus indirectly to climate change (1). Sustainable consumption is essential because careful choices made today by politicians, business, but also by individuals, can go a long way to leaving a world that meets the needs of future generations.

Private households are estimated to be responsible for 72% of global greenhouse gas (GHG) emissions (1). Of these, mobility, food consumption, and comfortable living are the dominant components of the "household footprint" (1). Household decisions, especially in Western countries such as Austria, play a key role in achieving the climate goals of the Paris Agreement (2, 3). The fact is, however, that the central role of individuals in contributing to climate change is too little addressed by the general population and policymakers. Climate policy debates fixate primarily on innovative technologies with more efficient production systems, without discussing the relevance of changes in consumer behavior. However, it is assumed that technological innovations in the field of resource use will not be sufficient to compensate for the immense environmental impacts of our consumption behavior (4). Therefore, sustainable production and resource use must be accompanied by the establishment of sustainable consumer behavior within the population (5).

In Germany, 76% of total mileage is accounted for by individual car use, with the vehicle being used for leisure activities such as vacations, hobbies, meeting friends, etc. in almost half of the usage (7). This distribution has remained unchanged in recent decades and, despite rising fuel prices, shows no tendency to change (6). The mobility sector is responsible for about 34% of household emissions, closely followed by food with 30% (6). Despite the current and profound understanding of the negative impact of motor vehicles on climate, numerous studies confirm a persistent behavioral permanence of automobile use (8-10). In addition, 2019 showed a new record in the number of airline passengers in Germany, while rail use remained steady, which in turn drives up GHG emissions (11, 12).

Our current eating habits, especially the production and consumption of animal products, have direct and indirect consequences on the environment and thus also on climate change. Animal agriculture is responsible for an estimated half of all GHG emissions, as animal agriculture not only leads to direct GHG emissions, but also indirectly through immense land use and heavy water consumption (13). In addition, about one-third of the food produced for human consumption worldwide is wasted, which further causes huge GHG emissions (14). In Europe, food waste by a single person is estimated to be around 95-115 kg/year (14). The goals of the Paris Climate Agreement cannot be met with the current global dietary trend, even if fossil fuel emissions were stopped instantaneously (15). A shift to a plant-based diet could reduce GHG emissions by 49% and land use by 76% (16). A trend toward plant-based protein production has the greatest potential CO2 savings of any current decarbonization effort (17). Thus, a plant-based food system can be considered the most effective climate change mitigation measures (17).

Buildings have significant energy consumption globally and regionally. The majority of GHG emissions occur during the occupancy phase within the living space to provide comfort (18). Heating, ventilation, air conditioning, water treatment, lighting, and maintenance are among the main drivers of household energy use (19). In European countries, energy use within the living space contributes about 20% to the household CO2 footprint per capita (3). Incorporating renewable energy is an effective way to enable zero-carbon, more sustainable housing. For example, solar energy in the form of heating and cooling can be used to heat and cool buildings. In addition, photovoltaic systems installed directly on site could generate electricity for buildings. This electricity can be used on demand and stored to be called upon in the event of increased electricity demand. Similarly, the incorporation of wind energy, geothermal energy, and hydrogen fuel can contribute to zero-emission building use. (18)

The fast fashion industry is the second largest polluter after the oil industry, responsible for approximately 8% of global GHG emissions and 20% of global water consumption (20). Up to 1900 different chemicals used during the fast fashion garment manufacturing process have been detected in wastewater (21). On average, a garment is worn only four times before it is disposed of, so around 92 million tons of clothing end up in landfills and used clothing containers every year (22). The fast fashion industry stands for short-livedness, because today's trend is tomorrow's trash. In order to ensure more environmental protection and sustainability as a consumer, clothing that has already been purchased should be treated with care and, if new clothing is needed, fair fashion labels should be chosen or second-hand goods should be purchased.

Our consumer behavior contributes immensely to climate change. In conclusion, it can be said that the greatest potential for environmental relief at the individual level lies in the areas of mobility, nutrition, housing and clothing purchasing. Individuals who start with these measures can act most effectively against environmental pollution and the associated climate change. From the political side, it should be determined what obstacles are present and what motivations are necessary to guide the individual toward a low-carbon, environmentally friendly and thus sustainable lifestyle.