Correct! It takes 3,781 liters of water to make one pair of jeans, from the production of the cotton to the delivery of the finished garment to a store. Textile manufacturing uses 20% of the world’s clean water each year.

Most toilets produced since 1994 use less than 1.6 gallons (6.1 liters) per flush. Older toilets might use twice that amount, and new low-flow toilets may use less than 1.3 gallons (4.9 liters).

An e-reader represents not just one book but an entire bookshelf, so having more books on the e-reader reduces the environmental burden per book. ... If you read a limited number of books, the paper book will most likely limit your greenhouse gas emissions. But for heavy readers, e-books have a smaller carbon footprint.

Correct!

As you know from the carbon cycle, some processes, like photosynthesis, use up carbon dioxide quickly, while others, like carbon dioxide captured by weathering of rocks, operate over many thousands of years. Thus, you can't put your finger on the exact life span of a given molecule of CO2 in the atmosphere.

The bottom line is that once emitted, CO2 continues to affect the climate for decades to millennia. That's why reducing emissions quickly is important. Because of the existing CO2 in the atmosphere, the Earth will continue to warm even after we stop burning fossil fuels.

The complexity of CO2 residence time is summed by Zeke Hausfather in Yale Climate Connections:

"Using a combination of various methods, researchers have estimated that about 50 percent of the net anthropogenic pulse would be absorbed in the first 50 years, and about 70 percent in the first 100 years. Absorption by sinks slows dramatically after that, with an additional 10 percent or so being removed after 300 years and the remaining 20 percent lasting tens if not hundreds of thousands of years before being removed."