In our opinion, designers should be both curious and well-informed. We can't help you out with the first trait, but for the sake of the second we're going to start regularly listing design research reference sources here on the blog that you may find useful.
We found a Denmark-based website called The World Counts that aggregates numbers from research institutions, news services and a variety of organizations around the world. TWC focuses on the intersection of consumption and sustainability, and the numbers they present--some of which are ticking upwards or downwards in real time, algorithmically-managed--can provide a good jumping-off point for those doing design research in those areas.
Some examples: How many liters of water have you, the average person, used today? What percentage of time do people in the Western world spend indoors? How many tons of steel have been recycled this year? How many tons of waste does the average household produce per year? What percentage of coral reefs do we have left? How many tons of resources were extracted from the planet this year?
"The World Counts gives you an overview of critical global challenges," reads the site's mission statement. "Awareness is the first step towards change!"
TWC also takes pains to link to all of their reference sources beneath each statistic, for those who wish to dive deeper into the numbers and/or verify their legitimacy.
Lastly, for the sake of inspiration as well as information, the site maintains a list of brands that they reckon are truly practicing sustainability.