As I discussed in my overview of hydroelectric power in 2008, the main barriers to new hydroelectric facilities are complex environmental studies, permitting issues, and water laws.

FORBES: Administration Lays the Groundwork for Hydropower Boom

Similarly, trying to contain the oil and limit the environmental impact is also complex, involving multiple technologies, the coordination of public agencies and private sector firms, and the mobilization of huge amounts of equipment and people.

FORBES: Let's Not Compound Complexity

Some worry about the infrastructural and environmental impact of the massive complex the Saudis seek to build on the new ISA campus.

CENTERFORSECURITYPOLICY: Welcome to Faisal County

Now to turn the tide on this epidemic, we must confront the complex social and environmental conditions that help fuel the HIV epidemic in African-American communities.

WHITEHOUSE: Office of National AIDS Policy Blog

Many Americans suffer from it, and it is most likely caused by a complex set of genetic and environmental factors, it says.

CNN: STORY HIGHLIGHTS

As with Zytiga, the questions were far-ranging and complex: Does GAIA consider only the environmental impact of product ingredients, or does the assessment also look at their impact on human health?

FORBES: Diving Deeper: How High Should We Set the Bar?

Issues become more complex upon setting the jokes aside and considering serious economic and environmental concerns.

FORBES: When Washington Fails a Cost-Benefit Test

Such ills are caused by a complex stew of dozens of genes, as well as bad diet and other environmental factors, such as smoking.

FORBES: On The Cover/Top Stories

But the complex, multifaceted challenges and risks ahead call for a response which addresses the social, economic and environmental issues facing the world today in an integrated and comprehensive manner.

UNESCO: Rio+20: harnessing the potential of science to build green societies | United Nations Educational, Scientific and Cultural Organization