Even if we switch to all renewable energy sources, like solar, wind, and hydroelectric power, carbon emissions would persist. We need sustainable materials to complement renewable energy, because at current consumption levels we're on track to exhaust oil and natural gas in the next 50 to 55 years.
Many solar panels and turbines are made using materials like polymers, which are often derived from petrochemicals, for parts like blades, frames, backsheets, and encapsulants.
Additionally, the process of manufacturing the silicon used in solar cells can involve chemicals that are petrochemical-based.
While researchers are studying alternative materials, they have not been widely implemented or made available at the scale needed to immediately replace current methods.
Biomass can potentially provide many of the smaller feedstocks that fossil fuels do, but scaling up biomass production to meet all our current needs would require a significant amount of land, water, and other resources, which could have environmental and social impacts.
Additionally, the technology for converting biomass into more complex chemicals and materials is not developed. What exists is not as efficient or cost-effective as fossil fuel processes yet, meaning it can't support current population sizes or facilitate increases in production capacity.
Without some serious materials engineering sorcery to create materials from non-carbon resources, reducing carbon emissions too much would indirectly lead to population contraction and mass death. Renewable energy and financial growth are not proxies for material production. 

 Understood. We still have a renewable materials problem.