The phrase "are major difficulties" is correct and usable in written English.
It can be used when discussing significant challenges or obstacles in a particular context.
Example: "In the project, there are major difficulties that we need to address before moving forward."
Alternatives: "represent significant challenges" or "pose serious obstacles."
Climate change is a global problem and across the world there are major difficulties being experienced in reducing carbon dioxide (CO2) emissions.
There are major difficulties in using uncontrolled, large-scale surveillance data to unravel causal linkages and no attempt was made to quantitatively partition variation among competing causes.
The report said that as well as the financial drain of using non-permanent workers, it is also a safety issue if there are major difficulties with finding enough contracted staff.
Although it is logical that definitive evaluation of new therapies should be based on clinically meaningful outcomes, there are major difficulties to overcome when conducting treatment trials in multiple sclerosis (MS) with clinical endpoints such as relapse rate or progression in disability.
Arsenic contamination, groundwater depletion, flooding, drought, and salinity are major difficulties for the rural people to get safe drinking water from both surface and groundwater sources (Abedin et al. 2013).
All are major difficulties Americans deal with every day but none of it was deemed important enough for mention as a part of an address about the state of our union.
Those will be major difficulties facing the lawsuit, agreed Tom McGarity, a scholar who studies regulation at the University of Texas at Austin law school.
The main reason for this has been major difficulties in extracting sufficient DNA from older herbarium specimens that is of good enough quality for use in PCR amplification of the target sequences.
The result was major difficulties with maintaining structure, sustaining relationships, and managing finances.
In addition the previous control of other diseases in individuals from these countries, showed that there were major difficulties for treatment compliance, medical control and location at patients homes.
When extended across all 239 rearrangements involving chromosome 15, there is major difficulty constructing a sequence of progressive rearrangements that would spare the heterozygosity found in over 20 separate segments.
