The World Bank has lowering its forecasts for commodity prices overall, despite a slightly brighter outlook for oil, the Washington, D.C. organization announced on Wednesday.

Despite boosting its 2015 forecast for crude oil prices from US$53 per barrel in April to $57 per barrel, the World Bank expects commodity prices to remain weak in 2015, according to its latest commodity outlook report.

Energy prices are expected remain 39% below 2014 levels, on average, the report says, natural gas prices will decline in 2015, and coal prices will fall by 17%, it adds.

“Demand for crude oil was higher than expected in the second quarter. Despite the marginal increase in the price forecast for 2015, large inventories and rising output from OPEC members suggest prices will likely remain weak in the medium-term,” says John Baffes, senior economist at the World Bank, in a statement.

Downside risks to World Bank’s forecast include higher-than-expected non-OPEC production and continuing gains in OPEC output, the report says. Upside risks to the forecast include the continued closure of high-cost oil production, and rising geopolitical tensions.

Excluding energy, prices will be 12% below their 2014 levels this year, on average, according to the report. For example, metals prices will average 16% below 2014 levels this year, revised downward from 12% in April, the report says.

The largest decline is expected for iron ore (down 43%), according to the report, due to new low-cost mining capacity coming online this year and next (mainly in Australia). “Metals markets are adjusting by closures of high-cost operations and reduced investment. Markets will eventually tighten, in part due to large zinc mines closures, and as Indonesia’s ore export ban weighs on supplies, notably nickel,” the report says.

As for agricultural prices, they will average 11% below 2014 levels this year, revised downward from 9% in April, the report says. Fertilizer prices are likely to decline 5% on weaker demand and ample supply, it adds.

The report also examines the role of China and India in driving commodity demand over the past 20 years. It concludes that demand from China and, to a lesser extent, India, has significantly raised global demand for metals and energy, particularly coal, but has had a less significant impact on demand for food commodities.

“China and India have played a significant role in driving global consumption of industrial commodities especially since the early 2000s. Going forward, while demand from India is likely to be a major factor in shaping consumption of industrial commodities, China will be important in driving global demand for energy given its efforts in rebalancing growth,” says Ayhan Kose, director of the World Bank’s Development Prospects Group.