Why aren't we feeling the effects of ecological degradation?

One of the long held ideas in sustainable development is that any activities that cause ecological degradation will affect local wellbeing.  So if a farmer misuses the soil, the reduction in crop yields will hit him or her in the pocket.  But is this actually the case?  It turns out that it's quite difficult to show that ecological degradation has restricted farmers' wealth or reduced incomes.  In fact, most data show that poverty alleviation has risen despite widespread pollution, soil erosion and biodiversity losses - a curiosity coined by Raudsepp-Hearne et al (2010) as the Environmentalist's Paradox.  They concluded that the likely reason was a combination of three factors: wellbeing is dependent on rising food productivity and less affected by other ecosystem declines; technology has effectively decoupled wellbeing from nature; and there are time-lags between ecological decline and its effect on wellbeing - a potential time-bomb for the future.

But that was 2010.  In late 2012, Ray et al (2012) surveyed over 2.5 million crop census reports from across the world for the period 1961-2008.  They found that 23-37% of soybean, maize, rice and wheat areas were now  experiencing yield stagnation, and 3% of maize, 1% of rice and 1% of wheat areas had experienced a yield collapse.   Heat stress, loss of soil fertility, soil erosion, and pest and disease build-up all suggest that at least for world agriculture the time-lags are beginning to play out.   If the environment is biting back, we surely need to take more care of the 'ecological hand' that feeds us. 

Raudsepp-Hearne et al 2010. http://bioscience.oxfordjournals.org/content/60/8/576.full.pdf 
Ray et al 2012. http://www.nature.com/ncomms/journal/v3/n12/full/ncomms2296.html