He advised investment  managers to stress-test their  strategies in a range of simulated  worst-case scenarios to make sure  they could withstand downturns.  An advocate of integrating  thematic and behavioural investing  theories into an overall investment  strategies, Gardner also said longterm  investors should identify  future trends that could impact  investment returns.  Some themes he identified for  the next 10 years included:  • the shift in economic power  from West to East;  • extreme wealth inequalities  in many emerging nations,  particularly the oil-rich nations;  • energy, food and water  shortages; and  • demographic trends, which  include an aging population in the  West.  Speaking alongside Gardener,  AXA IM’s senior adviser for  responsible investment, Dr Raj  Thamotheram, talked about how  sustainability concerns should  play a major role in investment  decisions as they had the capacity  to substantially affect the value of  investments.  He pointed to the causes of the  global financial crisis and compared  them with a case study of the recent  BP oil spill in the Gulf of Mexico.  Thamotheram said the two  events shared underlying drivers.  These included:  • the degrading of regulatory  authority through extensive  lobbying;  • the inability to learn from  past mistakes;  • a narrow conception of risk;  and  • a focus on short-term returns  that were unsustainable.  Rather than treating  sustainability as a peripheral  concern, Thamotheram argued the  diminishing safety culture at BP  resulted in a number of incidents  that were unheeded until the final  spill occurred and resulted in an  environment catastrophe and wiped  US$40 billion in shareholder value  from the company.  He provided a number  of solutions, including more  transparent reporting and genuine  integration of sustainability  principles into investment  strategies.