"It is unclear at the moment exactly what the impact will be as we assess the damage to Japan’s growth," said McFarlane.
"But Japan represents six per cent of global GDP. If the worst came to the worst then we would only be likely to see something like a three per cent fall from the growth of the global economy."
The manager was speaking after global equity markets tanked due to news that manufacturing supply chains may be affected by the crisis.
Performance of indices over 3-months
Source: Financial Express Analytics
The FTSE has slumped nearly three per cent since the earthquake struck on Thursday night, as UK investors moved away from riskier assets. The Nikkei has fallen 17.5 per cent and the S&P 500 is also down 5.4 per cent, giving rise to concerns that the disaster may tip the world economy back into recession.
The Bank of Japan has injected 21trn yen to support the Japanese financial markets and alleviate investor fears. McFarlane, however, believes that the country has learnt a great deal from the Kobe earthquake in the mid 1990s.
"In 1995 there was a short, sharp shock to the Japanese economy, which was addressed quickly by three periods of fiscal stimulus," he said.
"The Bank of Japan has already reacted by flooding the market with liquidity and we will shortly see the start of fiscal stimulus."
A recent note from M&G said that M&G Japan fund manager Dean Cashman and M&G Japan Smaller Companies manager Max Godwin believe that a strong policy from the Bank of Japan is likely to be supportive for banks, which means valuations for financials remain attractive.
Chris Spear, who is managing director at Spear Financial, is also optimistic that the injection of capital, while creating a legacy of debt, will provide the necessary conditions for growth.
"I can remember learning at school about the rebuilding of German and Japanese cities after World War II," he said. "Then it was enormous loans from the US that made recovery possible. This is a similar situation."
"It feels a little crass to say, given the ongoing suffering in Japan, but, regrettably, I think the tsunami did create a buying opportunity. I had four clients yesterday asking to invest."
However, McFarlane is still wary of the threat of a full-scale nuclear disaster as Japanese engineers fight to control heating fuel rods at the Fukushima nuclear power plant.
"The nuclear element is providing a massive unknown entity. If it was purely the economic implication of the earthquake then I would say that the markets have over-reacted," he continued.
"But even if the nuclear situation doesn’t get any worse there will be huge power shortages leading to uncertainty about production. Markets, as we know, hate uncertainty."
McFarlane also said that other threats to global growth have not gone away. "What is just as important is the growth of the Chinese currency, the Middle East unrest and what is going on with the Eurozone debt crisis," he finished.