A risky environment for investment.

Floods in Europe. Heat waves in the United States. Snowfall in the deserts of the United Arab Emirates. These are among the unusual weather conditions witnessed in different parts of the world in the past five years, conditions that demonstrate how climate change is beginning to impact people. While governments negotiate targets for cutting down emissions of greenhouse gases—seen by bodies such as the Intergovernmental Panel on Climate Change as the most viable mitigation measure to slow down the processes causing global warming—the fallout from rapid climate change has already set alarm bells ringing in the financial sector. 
 
Institutional investors are realizing that taking environmental, social, and corporate governance, or ESG, issues onboard is in the long-term interest of the investments they hold. Not doing so could pose a financial risk to their investments. 
 
Yet, in the absence of any pressure from market regulators to disclose information on environmental issues, and given the focus of markets on short-term profit, companies are not always forthcoming with full disclosures on environmental risks. According to a May 2006 report titled Climate Risk and Energy in the Auto Sector: Guidance for Investors and Analysts on Key Off-Balance Sheet Drivers, by the Ceres network for socially responsible investment (SRI), investors and analysts are finding it difficult to assess automotive companies due to lack of disclosure from companies and uncertainty about the future course of U.S. energy and climate change policies. 
 
At the same time, market research firms—which give investors “buy” and “sell” advice—need to be educated about climate change and other nonfinancial risks. In the February 2004 study Values for Money: Reviewing the Quality of SRI Research, the European action groups SustainAbility and Swedish Foundation for Strategic Environmental Research showed that only 3 of 35 stock market research firms specializing in SRI actually analyzed the link between ESG issues and material impacts on investment value drivers. Most used generic research methodologies and gathered data primarily from the companies themselves with little, if any, verification. 
 
Today a number of initiatives seek to weave ESG factors into virtually every segment of the market. Most recently, the UN launched the Principles for Responsible Investment (PRI), and a pact for financial institutions known as the Equator Principles was just revised to broaden its scope and thereby extend environmental protection. The blending of sustainability and profitability can, however, seem at times an uneasy marriage, at others a battle royale.

IT has been observed by several authors, both from a study of human and experimental material, that tumours of glial origin are more common in males (Bodian and Lawson, 1952;Hopewell and Wright, 1969;Netsky, August and Fowler, 1950;Penman and Smith, 1954;Sato, 1963;Tooth, 1912). Some of these authors have suggested that testosterone may be an important factor in the induction and growth of glial tumours (Avtsyn and Yablonovskaya, 1964;Hopewell and Wright, 1969;Penman and Smith, 1954).
A previous study (Hopewell and Wright, 1969) has shown that a high percentage of glial tumours can be produced in male rats by the deep implantation of a carcinogenic pellet into the brain so that it impinges on the mitotically active sub-ependymal plate. It seemed possible, using this method of tumour induction in normal and castrated male rats, that the hypothesis that testosterone is important in the induction and growth of glial tumours could be tested.

MATERIALS AND METHODS
Under chloral hydrate anaesthesia (300 mg./kg. intraperitoneally) the brains of 20 4-6-week-old male Sprague Dawley rats received " deep " implantations of the carcinogen 3,4-benzopyrene so that the pellet involved the sub-ependymal plate of the lateral ventricle. The implantation was carried out as described previously (Hopewell and Wright, 1969).
At this time 10 of the rats were castrated by the surgical removal of the testes. On recovery the rats were returned to the animal rooms where they were fed on Dixon's 41B diet and water ad libituam. Rats were observed at regular intervals * Address from June 1, 1970: M.R.C. Radiobiology Unit, Churchill Hospital, Oxford. until death or until they were killed in extremis. At the time of death the head was removed, the brain exposed and fixed by immersion in a solution of 1% acetic acid in 10% formol-saline. A more general post-mortem examination was also carried out to ascertain causes of death other than from cerebral tumour.
After fixation the brains were dissected out and sliced coronally. Histological sections were prepared in the normal way and stained with Ehrlich's haematoxylin and eosin.
At the time of death one castrated animal was found to have the pellet superficially situated in error and in the following evaluation of the result this animal has been excluded. The first rat in each experimental group died prematurely from a cerebral abscess before the time required to produce a cerebral tumour. These animals have also been excluded from the evaluation of the results.
Time After Implantation (months)

RESULTS
The histograms in Fig. 1 show the time and cause of death of all the experimental animals. It can be seen that following a " deep " intracerebral implant of 3,4-benzopyrene into normal and castrated male rats a higher proportion of glial tumours developed in normal males (7 out of 9; 778%) as compared with castrated rats (4 out of 8; 50 0).
If the cumulative tumour incidence (expressed as a percentage of the total number of animals in the group) is plotted against time then it is also evident that tumours in normal males developed earlier than in castrated males. These results can be compared with previous results (Hopewell and Wright, 1969) which have been expressed in a similar way and super-imposed on Fig. 2.
The tumours produced were classified as gliomas, of various types, by their gross and histological appearance (Table I)  The above results confirm that the " deep " implantation of chemical carcinogen into the brain of rats, to involve the sub-ependymal plate, will produce a high proportion of tumours of glial origin. The results for male rats are comparable with those from a previous study (Hopewell and Wright, 1969) where both the percentage of tumours produced and the time of incidence were similar (77.8% as compared with 81.8% in the previous experiment).
The observation that the tumour incidence was reduced in castrated animals and that the interval between implantation and death was increased adds weight to the hypothesis that gliomas are in some way testosterone dependant. Whether testosterone influences the rate of growth (as suggested by Avtsyn and Yablonovskay, 1964) or the timing of onset in addition to the total incidence of tumours remains in doubt.
The observation, in man, that castration reduces the testosterone levels in plasma to approximately normal female levels (Coppage and Cooner, 1965) may explain why for castrated male rats the percentage of tumours produced and the time of incidence are similar to those produced in females.
I am grateful to Professor E. A. Wright for helpful discussion during the preparation of this paper. The technical assistance of Mr. Terence Desombre is also gratefully acknowledged.
This work was supported by the British Empire Cancer Campaign for Research and the National Fund for Research into Crippling Diseases.