As we inch closer to 2025, where U.S. automakers will need their car and truck fleets to average 24.5 miles per gallon, you'd expect the transportation sector's contribution to pollution to begin diminishing. That doesn't appear to be the case, according to a United Nations report due out on April 13. 

The report states that greenhouse-gas emissions by that year will be 71% above their 2010 levels. It appears that the 27% increase in auto sales to 2020, as predicted by IHS, will help offset our hard-earned successes thus far, in large part because Asia will continue driving demand as wealth spreads throughout countries such as China, India and Indonesia.

These estimates don't take into account any unforeseen technological advancements. We can get a small sense of what's to come in the efforts of Tesla Motors' (NASDAQ:TSLA) charge into electric vehicles and the use of variable cylinder technology by General Motors (NYSE:GM) and Honda Motor Co. (NYSE:HMC). Be sure to check out the following short clip for more.

This segment is from Tuesday's edition of Digging for Value, in which sector analysts Joel South and Taylor Muckerman discuss energy and materials news with host Alison Southwick. The twice-weekly show can be viewed on Tuesdays and Thursdays. It can also be found on Twitter, along with our extended coverage of the energy and materials sectors, @TMFEnergy.


Joel South and Taylor Muckerman have no position in any stocks mentioned. The Motley Fool recommends General Motors and Tesla Motors and owns shares of Tesla Motors. Try any of our Foolish newsletter services free for 30 days. We Fools don't all hold the same opinions, but we all believe that considering a diverse range of insights makes us better investors. The Motley Fool has a disclosure policy.